Ferdinand (1865–1927)

King of Romania from 1914, when he succeeded his uncle Charles I. In 1916 he declared war on Austria. After the Allied victory in World War I, Ferdinand acquired Transylvania and Bukovina from Austria-Hungary, and Bessarabia from Russia. In 1922 he became king of this Greater Romania. His reign saw agrarian reform and the introduction of universal suffrage.

Ferdinand (1861–1948)

King of Bulgaria 1908–18. Son of Prince Augustus of Saxe-Coburg-Gotha, he was elected prince of Bulgaria in 1887 and, in 1908, proclaimed Bulgaria's independence from Turkey and assumed the title of tsar. In 1915 he entered World War I as Germany's ally, and in 1918 abdicated.