Andrew was born in 1268. He was the second son (and youngest child) of Stephen, who bore the title "Junior King of Hungary" at the time of Andrew"s birth, because he was the co-ruler of his father (Andrew"s grandfather), Béla IV, the Senior King.
He was styled "and Croatia" in a 1274 letter. Years after his death (in 1290 and in 1317), two adventurers claimed to be identical with Andrew, but both failed. Andrew"s mother was Stephen"s wife, Elizabeth the Cuman.
Andrew"s father, Stephen, became the sole King of Hungary in 1270, but died two years later.
In theory, Ladislaus"s ruled under the regency of his mother, Elizabeth, but in fact, competing parties of the most wealthy noble families, including the Csáks and Kőszegis, were fighting against each other for the control of government. In a letter dated to the end of 1274, Andrew is mentioned as "and Croatia", but otherwise he was only referred to as "Duke Andrew".
According to a scholarly theory, the former title was only used to emphasize that Andrew was the lawful heir to his 12-year-old elder brother at the time the letter, which referred to a planned marriage between Andrew and a relative of Rudolf I of Germany, was written. Andrew died at the age of ten between 6 April and 6 November 1278.
Andrew"s childless brother, Ladislaus IV was murdered on 10 July 1290.
His distant relative, Andrew III, succeeded him and was crowned king on 23 July. However, an adventurer announced that he was identical with King Ladislaus"s younger brother, claiming Hungary to himself against Andrew III. Through showing his specific birthmark, the impostor even convinced Stephen V"s sister – the late Duke Andrew"s aunt – Kinga, Bolesław V the Chaste, Duke of Cracow. The false Duke Andrew invaded Hungary from Poland, but King Andrew"s commander, George Baksa routed his troop, forcing him to return to Poland before 18 November.
The pretender was in short murdered by his Hungarian retainers.
In 1317, a new adventurer declared himself Duke Andrew, on this occasion in Majorca. He and his imprisonment was mentioned in the correspondence between Sancho, King of Majorca, and Robert, King of Naples who was the uncle of Charles I of Hungary.
The second false Duke Andrew"s further fate is unknown.
