Barbara Zápolya (, 1495–1515) was Queen of Poland and Grand Duchess of Lithuania as the first wife of King Sigismund I the Old from 1512 to 1515. Marriage to Barbara represented an alliance between Sigismund and the House of Zápolya against the Habsburgs in succession disputes over the throne to the Kingdom of Hungary. The alliance was short-lived as the renewed Muscovite–Lithuanian War forced Sigismund to look for Habsburg allies. The marriage was loving, but short. Barbara was the mother of Hedwig, Electress of Bradenburg, but died soon after the birth of her second daughter Anna. Marriage plans She was the daughter of Stephen Zápolya, Palatine of Hungary and Count of Szepes, and the Polish princess Hedwig of Cieszyn of the Piast dynasty. Barbara was a younger sister of John Zápolya, the future King of Hungary. The family was well known for their wealth: Stephen had more than 70 castles in Hungary and Slovakia. Her father died in 1499, leaving the family in care of Hedwig's cousin, Casimir II, Duke of Cieszyn. Barbara probably spent her childhood in the Trenčín Castle and the court of Anne of Foix-Candale, Queen of Bohemia and Hungary. Sigismund I the Old was the fifth of six sons of Polish King Casimir IV Jagiellon. Not having any inheritance in either Poland or Lithuania, he lived in Buda, at the court of his elder brother King Vladislaus II of Hungary, in 1498–1501 and 1502–1506. At that time he became closer with the House of Zápolya. Sigismund mediated a dispute between his brother Vladislaus and the Zápolyas, who wanted to secure the throne of Hungary to John Zápolya by securing marriage between John and Vladislaus' first-born Anne of Hungary. Vladislaus refused, favoring the interests of Maximilian I, Holy Roman Emperor. The Hungarian nobles strongly opposed the increasing reach of the Habsburg dynasty and threatened to take up arms. The conflict lost its urgency when Vladislaus' son and heir Louis II of Hungary was born in July 1506. In August 1506, Alexander Jagiellon died without leaving an heir. Sigismund was elected as King of Poland and Grand Duke of Lithuania and faced growing ambitions of the Habsburgs not only in Hungary and Bohemia, but also in the State of the Teutonic Order in Prussia. That forced him to look for anti-Habsburg allies and Zápolyas in Hungary were the strongest. A royal marriage would strengthen Zápolya position in any