Charles I, also known as Charles Robert, was King of Hungary and Croatia from 1308 to his death. He was a member of the Capetian House of Anjou and the only son of Charles Martel, Prince of Salerno. His father was the eldest son of Charles II of Naples and Mary of Hungary. Mary laid claim to Hungary after her brother, Ladislaus IV of Hungary, died in 1290, but the Hungarian prelates and lords elected her cousin, Andrew III, king. Instead of abandoning her claim to Hungary, she transferred it to her son, Charles Martel, and after his death in 1295, to her grandson, Charles. On the other hand, her husband, Charles II of Naples, made their third son, Robert, heir to the Kingdom of Naples, thus disinheriting Charles.

Andrew III the Venetian was King of Hungary and Croatia between 1290 and 1301. His father, Stephen the Posthumous, was the posthumous son of Andrew II of Hungary although Stephen's older half brothers considered him a bastard. Andrew grew up in Venice, and first arrived in Hungary upon the invitation of a rebellious baron, Ivan Kőszegi, in 1278. Kőszegi tried to play Andrew off against Ladislaus IV of Hungary, but the conspiracy collapsed and Andrew returned to Venice.