Kronan (ship)

A map of Sweden's territorial gains and losses 1560–1815. Sweden was at its peak as a Baltic power in the years that Kronan served.

In the 1660s, Sweden was at its height as a European great power. It had defeated Denmark, one of its main competitors for hegemony in the Baltic, in both the Torstenson War (1643–45) and the Dano-Swedish War (1657–58). At the Treaties of Brömsebro (1645) and Roskilde (1658), Denmark had been forced to cede the islands of Gotland and Ösel, all of its eastern territories on the Scandinavian Peninsula, and parts of Norway. In a third war, from 1658 to 1660, King Charles X of Sweden attempted to finish off Denmark for good. The move was bold royal ambition in an already highly militarized society geared for warfare, a fiscal-military state.[2] Disbanding its armies would have required paying outstanding wages, so there was an underlying incentive to keep hostilities alive and let the army live off enemy lands and plunder. The renewed attack on Denmark threatened the trade interests of the leading maritime nations of England and the Dutch Republic by upsetting the balance of power in the Baltic. The Dutch intervened in 1658 by sending a fleet to stop the attempt to crush Denmark.[3] England also sent a fleet in November the same year, to assist Sweden in keeping the Sound Toll out of Danish and Dutch control. The English expedition failed as a result of adverse winter weather and the political turmoil that ended the Protectorate, and in the end, Charles' plans were thwarted.[4]

Charles X died in February 1660. Three months later, the Treaty of Copenhagen ended the war. Charles' son and successor, Charles XI, was only five when his father died, so a regency council—led by the queen mother Hedvig Eleonora—assumed power until he came of age. Sweden had come close to control over trade in the Baltic, but the war revealed the need to prevent the formation of a powerful anti-Swedish alliance that included Denmark. There were some successes in foreign policy, notably the anti-French Triple Alliance of England, Sweden, and the Dutch Republic. By early 1672, Sweden had improved its relations with France enough to form an alliance. The same year, King Louis XIV attacked the Dutch Republic, and in 1674 Sweden was pressured into joining the war by attacking the Republic's northern German allies. France promised to pay Sweden desperately needed war subsidies on condition that it moved in force on Brandenburg. A Swedish army of 22,000 men under Carl Gustaf Wrangel advanced into Brandenburg in December 1674 and suffered a minor tactical defeat at the Battle of Fehrbellin in June 1675. Though not militarily significant, the defeat tarnished the reputation of near-invincibility that Swedish arms had enjoyed since the Thirty Years' War. This emboldened Sweden's enemies, and by September 1675 Denmark, the Dutch Republic and the Holy Roman Empire were at war with Sweden and France.[5]

State of the fleet

By 1675 the Swedish fleet was numerically superior to its Danish counterpart (18 ships of the line against 16, 21 frigates against 11), but the Swedish ships were generally older and of poorer quality than those of the Danish fleet, which had replaced a larger proportion of its vessels with more modern warships. The Swedish side also had problems with routine maintenance, and both rigging and sails were generally in poor condition. Swedish crews lacked the level of professionalism of Danish and Norwegian sailors, who often had experience from service in the Dutch merchant navy, and the Swedish Navy lacked a core of professional officers while the Danish had seasoned veterans like Cort Adeler and Nils Juel. The Danish fleet was reinforced with Dutch units under Philip van Almonde and Cornelis Tromp, the latter an experienced officer who had served under Michiel de Ruyter.[6]

Detail of engraving of Stockholm from Suecia antiqua et hodierna by Erik Dahlberg and Willem Swidde, printed in 1693. The view shows the Swedish capital as a bustling port, and in the foreground the peak of Kastellholmen next to the royal shipyards on Skeppsholmen.

The First Anglo-Dutch War (1652–54) saw the development of the line of battle, a tactic where ships formed a continuous line to fire broadsides at an enemy. Previously, naval tactics had favored short-range firepower and boarding with intent to take prizes. After the mid-17th century, improved gunnery caused tactics to shift from close-quarter fighting to disabling or sinking opponents through superior, long-distance firepower. This entailed major changes in doctrine, shipbuilding, and professionalism in European navies from the 1650s onwards. The line of battle favored large ships that were heavily armed and robust enough to hold the line in the face of enemy fire. The increased centralization and concentration of power in the emerging nation-states during the late 17th century allowed for a great expansion of armies and navies, and new government shipyards began building much much larger ships. Sweden embarked on an expansive shipbuilding program in the late 1660s.[7]

Kronan was one of the most heavily armed warships in the world in 1672 when she was launched, a three-decker with 110 guns. The ship had three full gundecks with guns from bow to stern. Altogether there were seven separate levels, divided by six decks. Furthest down in the ship, above the keel, was the hold, and immediately above it, but still below the waterline, lay the orlop; both were used primarily for storage. Above the orlop were the three gundecks, two of them covered, while about half of the topmost gundeck was open to the elements in the ship's middle, or waist. The bow had one deck, making up the forecastle, and the stern had two decks, including a poop deck.[8]

Diagram of Kronan's deck structure based on a model by the Kalmar County Museum

During the first half of the 17th century, Swedish warships were built in the Dutch manner, with a flat, rectangular bottom with a small draft. This shipbuilding style was adapted mainly for smaller ships in the shallow coastal waters of the Netherlands, and allowed for quick construction, but these less sturdy vessels were generally unsuitable as warships and somewhat unstable in rough seas. When Kronan was built, the English approach to building had prevailed, giving hulls a more rounded bottom and greater draft, as well as a sturdier frame and increased stability. The stern was more streamlined below the waterline, which lessened resistance.[9]

The measurements for Kronan were recorded in contemporary navy lists. Its length from stem post to stern post was 53 m (174 ft); this was considerably shorter than the length if the bowsprit and beakhead were included. The width was 12.9 m (42 ft) and was defined as the widest point between the frames, excluding planking. The draft varied depending on how heavily she was laden, but with full stores, ammunition and armaments it would have been about 6.2–6.8 m (20–22 ft).[10] The height of the ship from keel to the highest mast was never recorded, but Kalmar County Museum has estimated it to have been at least 66 m (217 ft).[11]

Kronan's displacement – the ship's weight calculated by how much water it displaced while floating – is not known precisely, since there are no exact records of the dimensions. By using contemporary documents describing the approximate measurements, it has been estimated at around 2,300 tonnes. By its displacement in relation to the number and weight of guns, Kronan was over-gunned, though this was not uncommon for the era. European shipwrights had not been building three-deckers on a large scale before the 1650s; by the 1660s, designs were still quite experimental. Contemporary records show that English and French three-deckers tended to be rather unstable because they were built high, narrow and with too much artillery. Some English ships had to be reinforced with a "girdle" of built-up planking at the waterline to perform satisfactorily.[12] In rough seas these ships could be forced to close the lowest row of gunports, depriving them of their heaviest and most effective guns. In these situations they were effectively just over-priced two-deckers. Kronan's construction was not inherently flawed; the ship handled harsh weather conditions in 1675 and again only a week before capsizing, but she could be dangerous if handled poorly. Later, during the 18th century, ships with the same weight of guns had more tonnage to support their guns, usually weighing 3,000–5,000 tonnes, which made them more stable. When Kronan was built, she was the third or fourth largest ship in the world, but as the trend moved towards ever greater ships, she was surpassed by other large warships. At the time Kronan sank, she was down to seventh place.[13]

Armament

Salvaged cannons of various types from Kronan on display at Kalmar County Museum

According to the official armament plan Kronan was to be equipped with 124–126 guns; 34–36 guns on each of the gundecks and an additional 18 shared between forecastle and sterncastle decks. Guns were classed by the weight of the cannonballs they fired, varying between 3 and 36 pounds (1.3–15.3 kg). The guns themselves weighed from a few hundred kg (400–500 lbs) up to four tonnes (4.4 tons) with the heaviest pieces placed in the middle of the lower-most gundeck with successively lighter ones on the decks above. Kronan's most lethal weapons were the 30- and 36-pounders on the lowest gundeck which had a range and firepower that outclassed the armament of almost any other warship. The guns lighter than 18-pounders were primarily intended to inflict damage on the enemy's crew and rigging rather than the hull.[14]

According to modern research, the number of guns was considerably less than the official armament plan. At the time, armament plans regularly overstated the number of guns available. In reality, they were ideal estimations that seldom reflected actual conditions, either because of a lack of ordnance or because they were impractical when tested. Heavy 30- and 36-pounder guns were particularly difficult to find in sufficient numbers and lighter guns were frequently used instead. Going by the number of guns salvaged from Kronan in the 1680s (see "History as a shipwreck") and during the excavations in the 1980s the total comes to 105–110. The upper figure matches the calculations of the number of gunports on the remains of the wreck and the number of guns that could practically fit on the gun decks. The lower figure is the number of guns found in the 1980s excavations combined with the list of guns brought up during the salvage operations in the 1680s. The table below lists the number of guns, comparing the official 1671 armament plan to the calculations by naval historian Jan Glete.[14]

Distribution of guns

	1671 armament plan	Actual armament
Lower gun deck	12 36-pounders 16 30-pounders 4 24-pounders 2 18-pounders	8 36-pounders 8 30-pounders 10 24-pounders 4 long 24-pound chasers
Middle gun deck	36 24-pounders	4 heavy 24-pounders 16 light 24-pounders 6 heavy 12-pounders 4 long 12-pound stern chasers 2 8-pounders
Upper gun deck	36 light 12-pounders	10 heavy 12-pounders 10 light 12-pounders 2 10-pounders 2 8-pounders 2 heavy 6-pounders
Forecastle and sterncastle	20 6-pounders	16 6-pounders 6 3-pounders

Firearms, including muskets, on display at Kalmar County Museum

Several types of ammunition were available, each for different uses: round shot (cannonballs) against ship hulls, chain shot against masts and rigging, and canister shot (wooden cylinders filled with metal balls or fragments), which had a devastating effect on tightly packed groups of men. For boarding actions Kronan was equipped with 130 muskets and 80 matchlock or flintlock pistols. For close combat there were 250 pikes, 200 boarding axes and 180 swords.[15] During the excavations, large-caliber firearms were found – hakebössor, similar to blunderbusses; they were equipped with a small catch underneath the barrel which allowed them to be hooked over a railing to allow it to absorb the recoil of the charges. One hakebössa was still loaded with a small canister containing 20 lead balls that would have been used to clear enemy decks before boarding.[16]

In the early 1660s, a building program was initiated to expand the fleet and replace old capital ships. A new flagship was needed to replace the old Kronan from 1632.[18] The felling of vast quantities of timber that were required for the new admiral's ship had already begun in the winter of 1664–65.[19] Swedish historian Kurt Lundgren has estimated that 7–10 hectares (17–25 acres) of hundred-year-old oak forest was required for the hull and several tall, stout pines for the masts and bowsprit.[20]

The construction of Kronan began in October 1665, and the hull was launched on 31 July 1668. The shipwright of the Kronan, Francis Sheldon frequently came in conflict with the admiralty over the project. The navy administrators complained that he was unduly delaying the project and was spending too much time on his own private business ventures. The most aggravating contention was Sheldon spending time on exporting lucrative mast timber back home to England. Sheldon in turn complained about constant delays on the navy's part and lack of necessary funds to complete the project.[21] When the ship was launched, the slipway turned out to be too small and the rear section of the keel broke off during the launching. The admiralty demanded an explanation, but Sheldon's reply was that the damage was easily mended and that the problem was that the timber had been left to dry too long.[22] The conflict between the Admiralty and Sheldon dragged on for several years and caused constant delays. The sculptures were finished in 1669, but the rigging, tackling, and arming was drawn out a further three years, to 1672. The first occasion that the ship sailed was during the celebrations of Charles XI's accession as monarch in December 1672.[23]

A full-scale mockup of a section of one of the gundecks of Kronan as part of the exhibition at Kalmar County Museum

As one of the largest ships of her time, Kronan had a sizable crew. When she sank there were 850 people on board – 500 sailors and 350 soldiers. Historians working with the excavation of the wreck site have compared the ship with a middle-sized Swedish town of the late 17th century, describing it as a "miniature society". On board were male representatives of both lower and upper classes. (Women were allowed on navy vessels only within the limits of Stockholm archipelago; before reaching the open sea, they had to disembark.) As a community afloat, Kronan mirrored the contemporary social standards of military and civilian life, two spheres that were not strictly separated in the 17th century.[24]

The entire crew dressed in civilian clothing and there were no common navy uniforms. The Swedish army had only recently introduced standardized uniforms, something that was still uncommon in most of Europe. Clothing was differentiated according to social standing, with officers from the nobility dressed in elegant and expensive clothing while the ordinary crew dressed like laborers.[24] The only exceptions were the soldiers of the Västerbotten infantry regiment who had by the 1670s been equipped with the first "Carolingian"[25] uniforms in blue and white. The crew was sometimes assigned clothing or cloth with which to prepare "sailor garb" (båtmansklädning), which set them apart from the usual dress of the general populace. Officers maintained a large collection of fine clothing for use on board, but it is not known if it was used during everyday work. Quite likely they owned a set of clothes made from simpler, more durable and more comfortable fabrics which were more practical at sea.[26]

Recruitment was done by forced musters as part of the earlier form of the so-called allotment system. Sailors and gunners were supplied by a båtsmanshåll (literally "sailor household"), small administrative units in coastal regions that were assigned the task of supplying the fleet with one adult male for navy service. The soldiers on board were recruited from the army equivalents, knekthåll or rotehåll, ("soldier" or "ward household") from inland areas. Officers originated mainly from the nobility or from the upper middle class, and were paid through the allotment system or the income from estates designated for the purpose.[27] Higher-ranking officers most likely brought their personal servants on board. A valuable red jacket in bright red cloth that was worn by one of those who drowned on the ship could have belonged to one of these retinues.[28]

Inappropriate handling in rough weather was the most obvious cause for Kronan's sinking. Unlike Vasa, Kronan's sailing characteristics were not inherently flawed and the ship had served for several years in rough seas. During the work of the commission, artillery officer Anders Gyllenspak even made direct comparisons to Vasa. He testified that Kronan's ballast had been lightened at Dalarö at the beginning of the campaign and that she had not replenished her supply of drink, so that the ship had a shallower draft and would have been somewhat less stable than with full stores, though he did not blame this on Creutz.[49]

Why the Swedish fleet deviated from the original plan of engaging the allied force in home waters north of Öland has never been satisfactorily explained. According to Rosenberg and Gyllenspak on Kronan, Creutz made a turn because Uggla had signaled that he was going about. Rosenberg also believed that Bär on Nyckeln, admiral of the first squadron, was first to make a turn, and that Uggla considered it necessary to follow this unplanned maneuver to keep the fleet together.[50] Officers Anders Homman and Olof Norman, who both survived Svärdet, claimed that only Creutz as fleet commander could have made such a decision and that Uggla was only following Kronan's lead.[51] Witnesses who testified before the commission claimed that conflict between the officers was the reason that necessary precautions were not taken before Kronan came about. Rosenberg testified that Lieutenant Admiral Arvid Björnram and Major Klas Ankarfjäll had openly disagreed on how much sail should be set and how close to land the ship should sail.[52] According to Gyllenspak, senior fleet pilot Per Gabrielsson had voiced his concerns against turning in the rough weather, but no one had heeded his advice.[53]

Several scholars and authors have blamed Creutz for the loss of his ship, and he has been criticized as an incompetent sailor and officer who through lack of naval experience brought about the sinking.[54] Historian Gunnar Grandin has suggested that the intent of the maneuver was to take advantage of the scattered allied fleet, but that many of the officers on Kronan opposed the idea; Creutz and Björnram urged that the ship turn quickly to gain a tactical advantage while Ankarfjäll and Gabrielsson were concerned about the immediate safety of the ship. Grandin has also suggested that Creutz may have suffered a mental breakdown after the failure at Bornholm and the open dispute with his officers, which led to a rash and ultimately fatal decision.[55]

More recent views present the question of responsibility as more nuanced and complex – suggesting that Creutz cannot be singled out as solely responsible for the disaster. Historians Ingvar Sjöblom and Lars Ericson Wolke have pointed out that Creutz's position as admiral was comparable to that of a chief minister. He would have primarily been an administrator without the need for intimate knowledge of practical details; turning a ship in rough weather would have been the responsibility of his subordinates. Sjöblom has stressed that the disagreement between Major Ankarfjäll and Lieutenant Admiral Björnram on how much sail was needed wasted precious time in a situation where quick decisions were crucial.[56] Creutz was also unique as a supreme commander of the navy since he had no experience of military matters. The Swedish naval officer corps in the late 17th century lacked the prestige of army commanders, and seasoned officers and even admirals could be outranked by inexperienced civilians or army commanders with little or no naval background.[57] Maritime archaeologist Lars Einarsson has suggested that Creutz's "choleric and willful temperament" probably played a part, but that it could equally be blamed on an untrained and inexperienced crew and the open discord among the officers.[58] According to Sjöblom it is still unclear to historians whether there was a designated ship commander on Kronan with overall responsibility.[40]

A reconstruction of a diving bell of the type used for salvaging cannons from Vasa and Kronan in the late 17th century at an exhibition in the Marinmuseum, Karlskrona

The total cost of Kronan was estimated at 326,000 silver dalers in contemporary currency, and about half of the cost, 166,000 dalers, lay in the armaments. It was therefore in the interest of the Swedish Navy to salvage as many of the cannons as possible. In the early 1660s almost all the guns from Vasa had been brought up through greatly improved technology. Commander Paul Rumpf and Admiral Hans Wachtmeister were put in charge of the salvage of Kronan's cannons. With the help of diving bells, they were able to raise 60 cannons worth 67,000 daler in the summers (c. June–August) of 1679–86, beginning as soon as the war with Denmark had ended. In the 1960s, diving expert Bo Cassel made some successful descents to Vasa with a diving bell made according to 17th-century specifications. In 1986, further experiments were done on Kronan. The tests proved successful and the conclusion was that the 17th-century operations must have required considerable experience, skill and favorable weather conditions.[59] Though the conditions off Öland were often difficult, with cold water and unpredictable weather, and required a large crew, the expeditions were very profitable. Historian Björn Axel Johansson has calculated that the total cost for the entire crew for all eight diving seasons was less than 2,000 dalers, the value of one of Kronan's 36-pounder guns.[60]

MS Calmare Nyckel has been used as a diving platform for the excavations of Kronan since 1991, and is one of several vessels that have been used so far.[62]

The remains of Kronan lie at a depth of 26 m (85 ft), 6 km (3.7 mi) east of Hulterstad, off the east coast of Öland. Since her rediscovery in 1980, there have been annual diving expeditions to the site of the wreck from June to August. By Baltic Sea standards, the conditions are good for underwater archaeological work; the wreck site is far from land, away from the regular shipping lanes, and has not been affected by pollution from the land or excessive growth of marine vegetation. The visibility, especially in early summer, is good and can be up to 20 m. The seabed consists of mostly infertile sand that reflects much of the sunlight from the surface, aiding the surveying and documentation of the site with underwater cameras. Around 85% of the wreck site has been charted so far and Kronan has become one of the most extensive and well-publicized maritime archaeological projects in the Baltic Sea.[63]

Finds

More than 30,000 artifacts from Kronan have been salvaged and cataloged, ranging from bronze cannons of up to four tonnes to small eggshell fragments.[63] There have been several discoveries of considerable importance, and some of unique historical and archaeological value. One of the first finds was a small table cabinet with nine drawers containing navigational instruments, pipe-cleaning tools, cutlery and writing utensils, which most likely belonged to one of the officers.[64] As a flagship, Kronan carried a large amount of cash in the form of silver coins. Besides wages for the crew, a war chest was required for large, unforeseen expenses. In 1982, a collection of 255 gold coins was found, most of them ducats. The origin of the individual coins varied considerably, with locations such as Cairo, Reval (modern-day Tallinn), and Seville. Another 46 ducats were found in 2000.[65] The coin collection is probably the largest gold treasure ever encountered on Swedish soil, though it was not enough to cover large expenses, which has led to the assumption that they were the personal property of Admiral Lorentz Creutz.[66] In 1989, more than 900 silver coins were found in the remains of the orlop, at the time the largest silver coin collection ever discovered in Sweden. In 2005, a much larger cache of nearly 6,200 coins was uncovered and in 2006 yet another with more than 7,000 coins.[67] The silver treasure of 2005 consisted almost entirely of 4 öre-coins minted in 1675, which represented over 1% of the entire production of 4 öre-coins of that year.[68]

The remains of one of the violins and two drumsticks on display at Kalmar County Museum

Several musical instruments have been found, including a trumpet, three violins and a viola da gamba, all expensive objects that probably belonged to either the officers or the trumpeters. One of the trumpeters on board was a member of the admiral's musical ensemble and it is assumed that one of the particularly fine, German-made instruments belonged to him. Another remnant of the officers' personal stores was discovered in 1997, consisting of a woven basket filled with tobacco and expensive imported foodstuffs and spices, including ginger, plums, grapes and cinnamon quills.[69]

Approximately seven percent of the finds consist of textiles. Much of the clothing, particularly that of the officers and their personal servants, is well preserved and has provided information on clothing manufacture during the late 17th century, something that has otherwise been difficult to research based only on depictions.[70]

• Mary Rose, an English 16th-century carrack that was salvaged in 1982
• La Belle, the wreck of a French merchant ship salvaged in 1997
• Vasa, a Swedish warship which foundered and sank in 1628, was rediscovered in 1956, and was subsequently recovered
• Mars, a Swedish warship which sank in 1564, and was rediscovered in 2011

• Asker, Björn (2005) "Sjöofficerare till sjöss och till lands" in Björn Asker (editor) Stormakten som sjömakt: marina bilder från karolinsk tid. Historiska media, Lund. ISBN 91-85057-43-6; pp. 29–32. (in Swedish)
• Björlin, Gustaf, (1885) Kriget mot Danmark 1675–1679: läsning för ung och gammal. Norstedt, Stockholm. (in Swedish)
• During [Düring], Ebba, (1997) "Specific Skeletal Injuries Observed on the Human Skeletal Remains from the Swedish Seventeenth Century Man-of-War, Kronan" in International Journal of Osteoarchaeology, vol. 7; pp. 591–594.
• Einarsson, Lars (2001) Kronan. Kalmar läns museum, Kalmar. ISBN 91-85926-48-5 (in Swedish)
• Einarsson, Lars (2005) "Likplundring i Hulterstad år 1676" in Kalmar län: meddelande från Kalmar läns hembygdsförbund och Stiftelsen Kalmar läns museum. ISSN 0451-2715; pp. 52–58. (in Swedish)
• Einarsson, Lars (2005) "Ännu en silverskatt påträffad i vraket av regalskeppet Kronan" in Myntstudier, vol. 2005:3. ISSN 1652-2303.; pp. 14–16. (in Swedish)
• Ericson Wolke, Lars (2009) "En helt ny flotta – sjökrigen under 1600-talets sista årtionde", in Ericson Wolke & Hårdstedt, Svenska sjöslag. Medströms förlag, Stockholm. ISBN 978-91-7329-030-2 (in Swedish)
• Gainsford, Sara & Jonsson, Kenneth (2008) "2005 års skatt från regalskeppet Kronan" in Myntstudier vol. 2008:3. ISSN 1652-2303; pp. 3–17. (in Swedish)
• Glete, Jan (1993) Navies and Nations: Warships, Navies and State Building in Europe and America, 1500–1680, Volume One. Almqvist & Wiksell International, Stockholm. ISBN 91-22-01565-5
• Glete, Jan (1999) "Hur stor var Kronan? Något om stora örlogsskepp i Europa under 1600-talets senare hälft" in Forum Navale 55. Sjöhistoriska samfundet, Stockholm; pp. 17–25 (in Swedish)
• Glete, Jan (2002) "Kronans artilleri. Kort genomgång av arkivmaterial och data om bärgade kanoner", unpublished paper, Stockholm University.
• Glete, Jan (2010) Swedish Naval Administration, 1521–1721: Resource Flows and Organisational Capabilities. Brill, Leiden. ISBN 978-90-04-17916-5
• Golabiewski Lannby, Monica, (1988) The Goldtreasure from the Royal Ship Kronan at the Kalmar County Museum. Kalmus, Kalmar. ISBN 91-85926-09-4
• Gyllengranat, Carl August (1840) Sveriges sjökrigs-historia i sammandrag. Karlskrona, Ameen. (in Swedish)
• Isacson, Glaes-Göran (2000) Skånska kriget 1675–1679, Historiska media, Lund. ISBN 91-88930-87-4 (in Swedish)
• Johansson, Björn Axel (editor, 1985) Regalskeppet Kronan. Trevi, Stockholm. ISBN 91-7160-740-4 (in Swedish)
• Johansson, Björn Axel (1993), "Med dykarklocka på regalskeppet Kronan" in Ryde, Torsten (editor) "-se över relingens rand!" Festskrift till Anders Franzén. ISBN 91-7054-711-4; pp, 124–158 (in Swedish)
• Kronanprojektet (1992) Rapport över 1991 års marinarkeologiska undersökningar vid vrakplatsen efter regalskeppet Kronan. Kalmar läns museum, Kalmar. (in Swedish)
• Kronanprojektet (2007) Rapport över 2006 års marinarkeologiska undersökningar vid vrakplatsen efter regalskeppet Kronan. Kalmar läns museum, Kalmar. (in Swedish)
• Kronanprojektet (2008) Rapport över 2007 års marinarkeologiska undersökningar vid vrakplatsen efter regalskeppet Kronan. Kalmar läns museum, Kalmar. (in Swedish)
• Lundgren, Kurt (1997) Stora Cronan: Byggandet Slaget Plundringen av Öland En genomgång av historiens källmaterial. Lenstad Bok & Bild, Kristianstad. ISBN 91-973261-5-1. (in Swedish)
• Lundgren, Kurt (2001) Sjöslaget vid Öland. Vittnesmål – dokument 1676–1677. Lingstad Bok & Bild, Kalmar. ISBN 91-631-1292-2 (in Swedish)
• Pousette, Mary (2009) "Klädd ombord" in Schoerner, Katarina (editor) Skärgård och örlog: nedslag i Stockholms skärgårds tidiga historia. Kungl. Vitterhets Historie och Antikvitets Akademien, Konferenser 71. Stockholm. ISBN 978-91-7402-388-6 (in Swedish)
• Rodger, Nicholas A. M. (2004) The Command of the Ocean. A Naval History of Britain 1649–1815. Allen Lane, London. ISBN 0-7139-9411-8
• Rystad, Göran (editor, 2005) Kampen om Skåne. Historiska media, Lund. ISBN 91-85057-05-3 (in Swedish)
• Sjöblom, Olof (2003) "Slaget vid Öland 1676: Kronan går under" in Ericson [Wolke], Hårdstedt, Iko, Sjöblom & Åselius, Svenska slagfält. Wahlström & Widstrand, Stockholm. ISBN 91-46-20225-0 (in Swedish)
• Soop, Hans (2007) Flytande palats: utsmyckning av äldre svenska örlogsfartyg. Signum, Stockholm. ISBN 978-91-87896-83-5 (in Swedish)
• Unger, Gunnar (1909) Illustrerad Svensk Sjökrigshistoria omfattande tiden intill 1680. Bonnier, Stockholm. (in Swedish)
• Villner, Katarina (2012) Under däck: Mary Rose – Vasa – Kronan. Medström, Stockholm. ISBN 978-91-7329-108-8 (in Swedish)
• Zettersten, Axel (1903) Svenska flottans historia åren 1635–1680. Norrtälje tidnings boktryckeri, Norrtälje. (in Swedish)

• Einarsson, Lars (1994) "Present maritime archaeology in Sweden: the case of Kronan" in Schokkenbroek, J.C.A. (editor), Plying between Mars and Mercury: political, economic and cultural links between the Netherlands and Sweden during the Golden age: papers for the Kronan symposium, Amsterdam, 19 November 1993. NIVE for the Swedish Embassy, The Hague.; pp. 41–47
• Einarsson, Lars & Morzer-Bruyns, W.F.J. (2003) "A cross-staff from the wreck of the Kronan (1676)" in International Journal of Nautical Archaeology, v. 32; pp. 53–60
• Franzén, Anders (1981) HMS Kronan : The Search for a Great 17th Century Swedish warship. Royal institute of technology library [Tekniska högskolans bibliotek], Stockholm.
• Franzén, Anders (April 1989). "Kronan — Remnants of a Mighty Warship". National Geographic. Vol. 175, no. 4. pp. 438–464. ISSN 0027-9358. OCLC 643483454.

Wikimedia Commons has media related to Kronan (ship, 1672).

• Officiell website – hosted by Kalmar County Museum
• Kalmar läns museum – organizers of the Kronan Projekt and the site of several permanent exhibitions of finds from the ship
• Kronan at the Nordic Underwater Archaeology website