Duke of Lancaster

There were three creations of the Dukedom of Lancaster during the fourteenth and fifteenth centuries. The first creation was on 6 March 1351 for Henry of Grosmont, 4th Earl of Lancaster, a great-grandson of Henry III; he was also 4th Earl of Leicester, 1st Earl of Derby, 1st Earl of Lincoln and Lord of Bowland. When he died in 1361 the peerage became extinct.

The second creation was on 13 November 1362, for John of Gaunt, 1st Earl of Richmond and third surviving son of King Edward III.[2] He became Henry of Grosmont's son-in-law through his marriage to Blanche of Lancaster, Henry's second daughter and eventual heir. When Gaunt died on 4 February 1399 the dukedom passed to his son, Henry of Bolingbroke, 1st Duke of Hereford. Later that same year Bolingbroke usurped the throne of England from Richard II, becoming Henry IV, at which point the Dukedom merged in the Crown.

Henry re-created the dukedom on 10 November 1399 for his eldest son Henry of Monmouth, Prince of Wales. In 1413 Monmouth ascended the throne as King Henry V and the dukedom merged in the crown again, where it has remained ever since.

Nevertheless, the title continues to be used to refer to the monarch in relation to Lancashire and the Duchy of Lancaster, the estate associated with the former dukedom. It was customary at formal dinners in the historic county boundaries of Lancashire and in Lancastrian regiments of the armed forces for the Loyal Toast to be announced as "The King, Duke of Lancaster". In addition, in Lancaster it is still common to hear the national anthem sung as "God save our gracious King, long live our noble Duke".[3][4] However, the legal basis for the sovereign to use the title has been disputed as the right to the title may have had different heirs to the right to the duchy’s lands. In particular, George V was given legal advice that it was “extremely unlikely” that he was the Duke of Lancaster.[5]

First creation, 1351–1361

Duke	Portrait	Birth	Marriage(s)	Death
Henry of Grosmont House of Plantagenet also Earl of Derby (1337), Earl of Leicester (1345), Earl of Lancaster (1345), Earl of Lincoln (1349), Earl of Moray (1359), Lord of Beaufort and Nogent (1345)		c. 1310 Grosmont Castle son of Henry, 3rd Earl of Lancaster and Maud Chaworth	Isabel of Beaumont c. 1337 2 children	23 March 1361 Leicester Castle aged 50–51
Henry of Grosmont died in 1361 without male issue.

Second creation, 1362–1399

Duke	Portrait	Birth	Marriage(s)	Death
John of Gaunt House of Lancaster (founder) also Duke of Aquitaine (1390), Earl of Richmond (1342–1372), Earl of Leicester, Earl of Lancaster, Earl of Derby, Baron of Halton (1361)		6 March 1340 Ghent son of Edward III and Philippa of Hainault	Blanche of Lancaster 19 May 1359 – 12 September 1368 8 children Constance of Castile 21 September 1371 – 24 March 1394 2 children Katherine Swynford 13 January 1396 4 children	3 February 1399 Leicester Castle aged 58
Henry Bolingbroke House of Lancaster also Duke of Hereford (1397), Earl of Northampton (1337)		c. April 1367 Bolingbroke Castle son of John of Gaunt and Blanche of Lancaster	Mary de Bohun c. 1381 – 4 June 1394 6 children Joan of Navarre 7 February 1403 no children	20 March 1413 Westminster aged 46
Henry Bolingbroke seized the throne as Henry IV in 1399, and all of his titles merged with the crown.

Third creation, 1399–1413

Duke	Portrait	Birth	Marriage(s)	Death
Henry of Monmouth House of Lancaster also Prince of Wales and Earl of Chester (1399), Duke of Cornwall (1337), Duke of Aquitaine (1390)		16 September 1386 Monmouth Castle son of Henry IV and Mary de Bohun	Catherine of Valois 2 June 1420 1 child	31 August 1422 Château de Vincennes aged 35
Henry of Monmouth succeeded to the throne as Henry V in 1413, and his titles merged with the crown.

• Duchy of Lancaster website – Duke of Lancaster
• "Of the Countries Subject to the Laws of England," from Commentaries on the Laws of England, Introduction, chapter 4, by Sir William Blackstone, 1765 (see text following footnote 72)