Charles IV (Czech: Karel IV.; German: Karl IV.; Latin: Carolus IV; 14 May 1316 – 29 November 1378), also known as Charles of Luxembourg, born Wenceslaus (Czech: Václav, German: Wenzel), was the first King of Bohemia to become Holy Roman Emperor. He was a member of the House of Luxembourg from his father’s side and the Bohemian House of Přemyslid from his mother’s side; he emphasized the latter due to his lifelong affinity for the Bohemian side of his inheritance, and also because his direct ancestors in the Přemyslid line included two saints.
He was the eldest son and heir of John of Bohemia, King of Bohemia and Count of Luxembourg, who died at the Battle of Crécy on 26 August 1346. His mother, Elizabeth, Queen of Bohemia, was the sister of Wenceslaus III, King of Bohemia and Poland, the last of the male Přemyslid rulers of Bohemia. Charles inherited the County of Luxembourg from his father and was elected king of the Kingdom of Bohemia. On 2 September 1347, Charles was crowned King of Bohemia.
On 11 July 1346, the prince-electors chose him as King of the Romans (rex Romanorum) in opposition to Louis IV, Holy Roman Emperor. Charles was crowned on 26 November 1346 in Bonn. After his opponent died, he was re-elected in 1349 and crowned King of the Romans. In 1355, he was crowned King of Italy and Holy Roman Emperor. With his coronation as King of Burgundy in 1365, he became the personal ruler of all the kingdoms of the Holy Roman Empire.