伊凡三世
Helena was born in the Despotate of the Morea in 1431, the eldest daughter and child of Thomas Palaiologos, Despot of the Morea and Catherine Zaccaria of Achaea. She had two younger brothers, Andreas Palaiologos and Manuel Palaiologos, and a sister, Zoe, who would become the wife of Ivan III of Russia. Her maternal grandparents were Centurione II Zaccaria and Creusa Tocco. Her first cousin, also Helena Palaiologina, became Queen consort of Cyprus.