Constantine XI Palaiologos
Helena, possibly named after her great-grandmother Empress Helena Dragaš, was the eldest surviving child of Ivan III, Grand Prince of Moscow, and his second wife Sophia Palaiologina, niece of the last Byzantine Emperor Constantine XI Palaiologos. Helena was an older sister of Grand Prince of Moscow Vasili III of Russia. Little is known about Helena's childhood in Moscow, but it is known that she was literate and very attractive.