Anna of Masovia Parents Siemowit IV Alexandra of Lithuania Children Siblings Trojden II of Płock Jadwiga of Masovia Amelia of Masovia Cymburgis of Masovia Casimir II of Masovia Catherine of Masovia Władysław I of Masovia Aleksander Mazowiecki Maria of Masovia Siemowit V of Masovia Euphemia of Masovia Partners Michael Žygimantaitis