Ferdinand was born in Romania in 1865. His uncle, King Carol, a relative of Kaiser Wilhelm II, was strongly pro-German. Ferdinand was a close friend of Emperor Franz Josef and shared these views. However, he was also influenced by his British wife and on the outbreak of the First World War, argued for neutrality, unlike the king, who favoured joining the Central Powers.

After the death of King Carol in October 1914, Ferdinand inherited the throne. In the summer of 1916 Ferdinand decided to join the Allies against the Central Powers. Ferdinand, who attended the Paris Peace Conference, died in 1927.