In 1918, after the collapse of the Russian Empire, Azerbaijan became part of Transcaucasian Democratic Federative Republic. After the establishment of the Baku Commune in April 1918, clashes began in the city of Baku and other uyezds within the Baku Governorate, called the March Days, during which 12,000 Azerbaijanis and other Muslims and 2,500 Armenians died.