text: The Danube Flotilla was more modern, and consisted of four river monitors (Lascăr Catargiu, , Ion C. Brătianu and Alexandru Lahovari) and eight British-built torpedo boats. The four river monitors were built in 1907 at Galați. They were armed with three 12-cm cannons each. In 1918, Mihail Kogălniceanu was converted to a sea-going monitor. The British torpedo boats of the Căpitan Nicolae Lascăr Bogdan class were built during 1906–1907 and weighed 50 tons each. There were also approximately six older gunboats used for border patrol and as minelayers, and other auxiliary ships used for transport or supply. The Romanian Navy had a secondary role during World War I and only had light losses. The river monitors participated in the defense of Turtucaia and later secured the flank of the Romanian and Russian defenders in Dobruja. The main success of the war was the mining of an Austro-Hungarian river monitor.
  Romanian Navy during the interwar period
  Following the end of World War I, the Kingdom of Romania took possession of three Austro-Hungarian river monitors (renamed after the newly incorporated territories of Ardeal, Basarabia and Bucovina), and in 1921 purchased four Italian patrol boats. These ships, together with the ones already in service, made Romania's Danube flotilla the most powerful riverine fleet in the world until World War II.