The Bombardment of Belgrade was an Austro-Hungarian naval and artillery attack on the Serbian capital during the night of 28–29 July 1914, marking the opening engagement of World War I. Carried out by the Austro-Hungarian Danube Flotilla and supporting artillery across the Sava River, it was the first act of hostilities following the declaration of war on Serbia earlier that day.
Shortly after midnight, the river monitor SMS Bodrog fired on the city, joined by SMS Temes and SMS Szamos, in what is widely regarded as the first shot fired in the First World War. News of the bombardment prompted Tsar Nicholas II to order the general mobilisation of the Imperial Russian Army, accelerating the July Crisis into a continental conflict.