The first battle of Lonato (31 July 1796) was an early setback during the first Austrian attempt to lift Napoleon's siege of Mantua. Faced with the collapse of their position in northern Italy the Austrians were forced to move an army from the Rhine in an attempt to retrieve the situation. General Dagobert Würmser decided to launch a three-pronged assault on the French around Mantua. He led the main column down the Adige valley. To his left General Szoboszio advanced towards Verona, and to his right General Quosdanovich advanced down the Chiese valley, to the west of Lake Garda, heading for Brescia.
On 28 July the Austrians came into contact with Napoleon's covering forces in both the Adige and Chiese valleys, and forced the French to retreat south. The only French forces west of Lake Garda were 4,000 men under General Sauret posted at Salo, while 8,000 men of the reserve were at Castiglione, to the south of the lake.
On 30 July Quosdanovich captured Brescia and threatened to cut Napoleon's lines of communication west to Milan. At the same time Würmser was fighting his way down the Adige. Napoleon decided that his best chance of success was to concentrate all of his forces at the southern end of Lake Garda and defeat each Austrian detachment in turn.
Quosdanovich was Napoleon's first target. On 31 July Quosdanovich's advance guard, 4,000 men under General Ott, had reached Lonato, twelve miles to the east of Brescia and close to the south western tip of Lake Garda. On the same day Napoleon's main army had already crossed the Minco, and was heading west.
The first clash came when General Despinoy's advance guard ran into the Austrians in Lonato. Despinoy attacked Ott's position, but was repulsed, and was forced to retreat east. The situation was saved with Dallemagne's brigade from Masséna's division arrived on the scene. Ott was now badly outnumbered, and retreated back to Brescia.
While Ott was fighting around Lonato, Würmser with the main Austrian column made a dash for Mantua, reaching the city on 2 August. Although this did allow him to throw much needed supplies into the city, it soon became clear that this move had been a mistake (Würmser may had misinterpreted Napoleon's move north west to Lake Garda as the first stage of a retreat towards Milan). Napoleon was now ideally placed between two Austrian armies which were too far apart to cooperate. Realising this Quosdanovich made an attempt to advance south east to make contact Würmser, but was defeated (Second battle of Lonato, 3 August 1796) and was forced to retreat north into the mountains. This allowed Napoleon to concentrate all of his efforts against Würmser, who suffered a heavy defeat at Castiglione (5 August 1796).