This area was populated in prehistoric times and colonized during the Imperial Roman times; it formed a community with Nago, castle residence of the Counts d'Arco. In 1439 Torbole was involved in the Third Lombard War (1438), between the Duchy of Milan and the Republic of Venice. The latter dominated the eastern side of the lake (the Riviera). In order to gain supremacy on Lake Garda and help the Venetian condottiero Gattamelata, in freeing Brescia from the Milanese siege, the Venetians transported twenty-five boats and six galleys from the Adriatic Sea up the River Adige to the fluvial harbour of Mori. From here the boats were hauled further by oxen and manual labour until they could be launched into Lake Loppio, then further hauled along the slopes of Monte Baldo into Lake Garda at Torbole. This exploit cost 240 oxen and 15,000 ducats. In April 1440 the small Venetian fleet destroyed Visconti's fleet and conquered Riva del Garda.