Ferdinand I was the King of Romania from 1914 until his death in 1927. During his rule, Romania fought in World War I against the Central Powers and stopped the German advance into Moldavia. Romania was later forced to conclude an unfavorable treaty but Ferdinand refused to sign it. When Allied forces advanced, Romania re-entered the war on the side of the Allies. After the war, territories of Bessarabia, Bukovina, and Transylvania were united with Romania. Ferdinand oversaw the greatly enlarged Romanian state and was crowned King of Romania in 1922 in a ceremony celebrating the union of Transylvania with Romania.