Emperor Napoleon I orders the annexation of the Papal States to the French Empire.

Napoleon Bonaparte, later known by his regnal name Napoleon I, was a French general and statesman who rose to prominence during the French Revolution and led a series of military campaigns across Europe during the French Revolutionary and Napoleonic Wars from 1796 to 1815. He led the French Republic as First Consul from 1799 to 1804, then ruled the French Empire as Emperor of the French from 1804 to 1814, and briefly again in 1815. He was King of Italy from 1805 to 1814 and Protector of the Confederation of the Rhine from 1806 to 1813.

The Papal States, officially the State of the Church, were a conglomeration of territories on the Italian peninsula under the direct sovereign rule of the pope from 756 to 1870. They were among the major states of Italy from the 8th century until the unification of Italy, which took place between 1859 and 1870, culminated in their demise.

The French Empire, known retroactively as the First French Empire, was the empire ruled by Napoleon Bonaparte, who established French hegemony over much of continental Europe at the beginning of the 19th century. It lasted from 18 May 1804 to 6 April 1814 and again briefly from 20 March 1815 to 7 July 1815, when Napoleon was exiled to Saint Helena.

May 17 is the 137th day of the year in the Gregorian calendar; 228 days remain until the end of the year.