 Venetian Istria fell to the Habsburg Monarchy (the Austrian Empire after 1804) according to the 1797 Treaty of Campo Formio but was subsequently seized by Napoleon in the 1805 Peace of Pressburg, forming part of the Kingdom of Italy.It was then incorporated into the French Empire as part of the Illyrian Provinces in 1809.In 1815, after Napoleon had been defeated, the territory was returned to Austria as part of the Kingdom of Illyria by the 1815 Congress of Vienna.