Revolutions of 1848 in the Austrian Empire: After a month-long siege, Venice, which had declared itself independent as the Republic of San Marco, surrenders to Austria.

The revolutions of 1848 in the Austrian Empire took place from March 1848 to November 1849. Much of the revolutionary activity had a nationalist character: the Austrian Empire, ruled from Vienna, included ethnic Germans, Hungarians, Poles, Bohemians (Czechs), Ruthenians (Ukrainians), Slovenes, Slovaks, Romanians, Croats, Italians, and Serbs; all of whom attempted in the course of the revolution to either achieve autonomy, independence, or even hegemony over other nationalities. The nationalist picture was further complicated by the simultaneous events in the German states, which moved toward greater German national unity.

Venice is a city in northeastern Italy and the capital of the Veneto region. It is built on a group of 118 islands that are separated by expanses of open water and by canals; portions of the city are linked by 438 bridges.

The Republic of San Marco or the Venetian Republic was an Italian revolutionary state which existed for 17 months in 1848–1849. Based on the Venetian Lagoon, it extended into most of Venetia, or the Terraferma territory of the former Republic of Venice, suppressed 51 years earlier in the French Revolutionary Wars. After declaring independence from the Habsburg Austrian Empire, the republic later joined the Kingdom of Sardinia in an attempt, led by the latter, to unite northern Italy against foreign domination. The subsequent First Italian War of Independence ended in the defeat of Sardinia, and Austrian forces reconquered the Republic of San Marco on 28 August 1849 following a long siege.