Carol II was King of Romania from June 8, 1930, until his forced abdication on September 6, 1940. As the eldest son of Ferdinand I, he became crown prince upon the death of his grand-uncle, King Carol I, in 1914. He was the first of the Hohenzollern kings of Romania to be born in the country, as both of his predecessors had been born in Germany and came to Romania only as adults. As such, he was the first member of the Romanian branch of the Hohenzollerns who spoke Romanian as his first language and was also the first member of his royal family to be raised in the Orthodox faith.

The King of Romania or King of the Romanians was the title of the monarch of the Kingdom of Romania from 1881 until 1947, when the Romanian Workers' Party proclaimed the Romanian People's Republic following Michael I's forced abdication.