Because of its position at the junction of seven roads, the army that held the town controlled access to most of Switzerland and points crossing the Rhine into southern Germany.
By mid-May 1799, the Austrians had wrested control of parts of Switzerland from the French as forces under the command of Hotze and Count Heinrich von Bellegarde pushed them out of the Grisons.
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.
[5] In mid-spring, the Austrians reached an agreement with Tsar Paul of Russia by which Alexander Suvorov would come out of retirement to assist Austria in Italy with another 60,000 troops.
[9] 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.
[10] 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.
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, control the northern access points of Zürich and force an engagement with Masséna.
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.
[13] Winterthur (/ˈvɪntərtʊər/; German pronunciation: [ˈvɪntərˌtuːr]) lies in a basin south and east of the Töss approximately 31 kilometers (19 mi) northeast of Zürich.
[14] The locale of a Roman settlement from 200 to 400, and the site of a medieval battle in 919, its location at seven crossroads gave it strategic importance in the effort to control north–south and east–west communication in the early days of the War of the Second Coalition.
Protecting the northern access to Zürich, Masséna gathered some of the best commanders he had available; eventually, three of them would become Marshals of France, and Tharreau, a dependable General of Division.
Not only had they been trounced in southwestern Germany, the legendary Alexander Suvorov was on his way to northern Italy with 60,000 Russians to take command of Coalition forces there.
Most threatening, Archduke Charles' main army lay less than a day away; in size alone, it could overwhelm him, or, if he withdrew to the west, its position cut off his avenue of withdrawal toward France.
[17] To prevent this merger of the Austrian forces, Masséna established a forward line centred at Winterthur, and under overall command of the experienced Jean Victor Tharreau.
Ney arrived with the reputation for boldness considered typical of cavalry officers, but with minimal experience in commanding mixed forces.
Anxious to prove himself but aware of protocols, he had hurried to Tharreau's headquarters, but had to wait for his letters of service before he could take command.
The Swiss-born Hotze had entered the military service of the Duke of Württemberg in 1758 and had been promoted to Rittmeister, or captain of cavalry; he had campaigned briefly in the Seven Years' War, but saw no combat.
[20] To prevent these two forces from joining with Archduke Charles' 100,000 men, on 22 May, Masséna and 23,000 troops of the Army of the Danube marched from Zürich in the direction of Winterthur.
Opposite him, Michel Ney, newly in command of his division of approximately 3,000 men, deployed his force around the heights, the so-called Ober-Winterthur, a ring of low-lying hills some 6 km (3.7 mi) north of the city.
[25] By mid-morning, Hotze's advanced guard had encountered moderate French resistance first from Roget's brigade, and then, almost immediately, from Gazan's.
[26] The Austrian advance troops quickly overran Gazan's weak brigade and took possession of the woods surrounding the village of Islikon.
[26] By mid-morning, Ney had moved toward the front with Gazan's brigade and he could see the enemy advancing toward him; still expecting Soult's reinforcements on his flanks, he anticipated an easy victory, like the one three days earlier in which Masséna's force had pounded Hotze's column at Frauenfeld.
From the ridge, Ney's rear guard maintained a steady stream of cannon fire on any of the Austrians who crossed the bridge and attempted to advance up the hill.
This proved effective, for Ney was again injured, this time in his left hand, and his second horse was killed; he relinquished command to Gazan, who organised the continued withdrawal from the position.
[32] Nicolas Oudinot, whose men had secured Neftenbach as part of the French forward line, held out for most of the day, but was forced to retreat 4 km (2.5 mi) to Pfungen in the late afternoon; his position there was not defensible and he was pushed further back to the outskirts of Zürich.