First Battle of Zurich

Map of Zürich, 1800

Initially, the rulers of Europe viewed the revolution in France as an event between the French king and his subjects, and not something in which they should interfere. As revolutionary rhetoric grew more strident, they declared the interest of the monarchs of Europe as one with the interests of Louis and his family; this Declaration of Pillnitz threatened ambiguous, but quite serious, consequences if anything should happen to the royal family.[3] The French position became increasingly difficult. Compounding problems in international relations, French émigrés continued to agitate for support of a counter-revolution. On 20 April 1792, the French National Convention declared war on Austria. In this War of the First Coalition (1792–1798), France ranged itself against most of the European states sharing land or water borders with her, plus Portugal and the Ottoman Empire. Although the Coalition forces achieved several victories at Verdun, Kaiserslautern, Neerwinden, Mainz, Amberg and Würzburg, the efforts of Napoleon Bonaparte in northern Italy pushed Austrian forces back and resulted in the negotiation of the Peace of Leoben (17 April 1797) and the subsequent Treaty of Campo Formio (17 October 1797).[4]

The treaty called for meetings between the involved parties to work out the exact territorial and remunerative details. Convened at a small town in the mid-Rhineland, Rastatt, the Congress quickly derailed in a mire of intrigue and diplomatic posturing. The French demanded more territory. The Austrians were reluctant to cede the designated territories. Compounding the Congress's problems, tensions grew between France and most of the First Coalition allies. Ferdinand of Naples refused to pay agreed-upon tribute to France, and his subjects followed this refusal with a rebellion. The French invaded Naples and established the Parthenopean Republic. Encouraged by the French Republic, a republican uprising in the Swiss cantons led to the overthrow of the Swiss Confederation and the establishment of the Helvetic Republic.[5] The French Directory was convinced that the Austrians were planning to start another war. Indeed, the weaker France seemed, the more seriously the Austrians, the Neapolitans, the Russians, and the English discussed this possibility.[6] In mid-spring, the Austrians reached an agreement with Tsar Paul of Russia by which the legendary Alexander Suvorov would come out of retirement to assist Austria in Italy with another 60,000 troops.[7]

The French Directory's military strategy in 1799 called for offensive campaigns on all fronts: central Italy, northern Italy, the Swiss cantons, the upper Rhineland, and Holland. Theoretically, the French had a combined force of 250,000 troops, but this was on paper, not in the field.[8] As winter broke in 1799, General Jean-Baptiste Jourdan and the Army of the Danube, at a paper strength of 50,000 and an actual strength of 25,000,[9] crossed the Rhine between Basel and Kehl on 1 March. This crossing officially violated the Treaty of Campo Formio.[10] The Army of the Danube advanced through the Black Forest and, by mid-March, established an offensive position at the western and northern edge of the Swiss Plateau by the village of Ostrach.[11] André Masséna had already pushed into Switzerland with his force of 30,000, and successfully passed into the Grison Alps, Chur, and Finstermünz on the Inn river. Theoretically, his left flank was to link with Jourdan's right flank, commanded by Pierre Marie Barthélemy Ferino, at the far eastern shore of Lake Constance.[12]

At Elgg, Hotze established his forward posts; although the winter snows had melted, the ground was still soggy and the streams were still in full spring flow.

The Austrians had arrayed their own army in a line from the Tyrol to the Danube. A force of 46,000 under command of Count Heinrich von Bellegarde formed the defence of the Tyrol. Another small Austrian force of 26,000 commanded by Friedrich Freiherr von Hotze guarded the Vorarlberg. The main Austrian Army—close to 80,000 troops under the command of Archduke Charles—had wintered in the Bavarian, Austrian, and Salzburg territories on the eastern side of the Lech river. At the battles of Ostrach (21 March) and Stockach (25 March), the main Austrian force pushed the Army of the Danube back into the Black Forest. Charles made plans to cross the upper Rhine at the Swiss town of Schaffhausen. Friedrich Freiherr von Hotze brought a portion (approximately 8,000) of his force west, leaving the rest to defend the Vorarlberg. At the same time, Friedrich Joseph, Count of Nauendorf, brought the left wing of the main Austrian force across the Rhine by Eglisau. They planned to unite with the main Austrian army, controlling the northern access points of Zürich and forcing an engagement with Masséna.[13]

By mid-May, French morale was low. They had suffered terrible losses at Ostrach and Stockach, although these had been made up by reinforcements. Two senior officers of the Army of the Danube, Charles Mathieu Isidore Decaen and Jean-Joseph Ange d'Hautpoul, were facing courts-martial on charges of misconduct, proffered by their senior officer, Jourdan. Jean-Baptiste Bernadotte and Laurent de Gouvion Saint-Cyr were sick, or claimed they were, and had left the army's encampments to recover their health. Masséna's force had been repelled by Hotze's army at Feldkirch, and forced to fall back, and LeCourbe's failure to push through against Bellegarde's Austrian force in the Tyrol, meant Masséna had to pull his southern wing back as well as his center and northern wing, to maintain communication with the retreating armies on his flanks. At this point, also, the Swiss revolted again, this time against the French, and Zürich became the last defensible position Masséna could take.[14]

After pushing the Army of the Danube out of the northern portion of the Swiss Plateau—the territory north of the Rhine and south of the Danube—following the battles at Ostrach and Stockach, Archduke Charles' sizable force—about 110,000 strong—crossed the Danube west of Schaffhausen, and prepared to join with the Vorarlberg Corps of Friedrich, Baron von Hotze before Zürich. During the month of May André Masséna, now commander of both the French Army of Helvetia and the Army of the Danube began pulling back his forces to concentrate towards Zürich. Charles crossed the Rhine at Stein with an advanced corps of 21 battalions and 13 squadrons under Nauendorf on 20 May, while two days later in the evening, Hotze crossed at Meiningen and Balzers with 18 battalions and 13 squadrons. On the 23rd the Archduke led 15 more battalions and 10 squadrons over the Rhine at Büsingen.[15][16]

Learning of the double-pronged advance, Masséna seized the opportunity to drive a wedge between the two Austrian commands and on 25 May launched attacks against Hotze's Corps to the east and Nauendorf's to the north. Hotze's advance troops under Petrasch were driven from Frauenfeld by Soult, while against the Archduke Michel Ney erupted from Winterthur, seized Andelfingen and threw back Nauendorf from Pfyn. Although the French were forced to withdraw on the appearance of Austrian reserves, nevertheless for a loss of 771 men they'd inflicted some 2,000 casualties and 3,000 prisoners on the Austrians.[17]

On the 27th Ney was wounded and his men driven from Winterthur, Masséna thereafter concentrated his forces at Zürich, closely pressed by the Archduke Charles and Hotze.

By the end of the month the French were positioned: Soult's Division was on the Zürichberg overlooking the open country to the north from an entrenched camp constructed by Andréossi. To his left Oudinot's Division lay in support, with Gazan's brigade in the town of Zürich itself. Tharreau's Division continued the line across the Aare, with troops under Lorge' guarding the left of the Rhine to Basel. To Soult's right Chabran guarded the south of Lake Zürich, with outposts stretched to link with the troops of Lecourbe' at Lucerne and the Andermatt valley. In all some 52,000 French and Swiss troops. The entrenchments on the Zürichberg were in a 5-mile long semi-circle from Riesbach to Hongg, but were incomplete.[18]

Charles decided to launch his main attack by the surest (though difficult) route, directly against the Zürichberg with his left and centre, holding his right wing back to protect his line of retreat.