Barbara Zápolya (1495–1515) was Queen of Poland and Grand Duchess of Lithuania as the first wife of King Sigismund I the Old. 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.