War of the Third Coalition

The War of the Third Coalition (French: Guerre de la Troisième Coalition) was a European conflict lasting from 1805 to 1806 and was the first conflict of the Napoleonic Wars. During the war, France and its client states under Napoleon I and its ally Spain opposed an alliance, the Third Coalition, which was made up of the United Kingdom, the Austrian Empire, the Russian Empire, Naples, Sicily, and Sweden.

Source: Wikipedia — War of the Third Coalition (CC BY-SA 4.0)