also known as the Crown of Saint Stephen, named in honour of Saint Stephen I of Hungary, was the coronation crown used by the Kingdom of Hungary for most of its existence; kings were crowned with it since the twelfth century. The Crown symbolized the King’s authority over the Lands of the Hungarian Crown (the Carpathian Basin), and it was a key mark of legitimacy. Through the history of Hungary, more than fifty kings were crowned with it, with the last being Charles IV in 1916. The only kings not so crowned were Wladyslaw I, John Sigismund Zápolya, and Joseph II.
Source: https://en.wikipedia.org/wiki/Holy_Crown_of_Hungary