Magnus III, Duke of Mecklenburg Member of the House of Mecklenburg, Prince-Bishop of Schwerin (1509–1550) Parents Ursula of Brandenburg Duke Heinrich V, Duke of Mecklenburg-Schwerin Children Siblings Ursula of Mecklenburg Sophie of Mecklenburg-Schwerin Philip, Duke of Mecklenburg Margaret von Mecklenburg-Schwerin Catherine de Mecklembourg-Schwerin Partners Elizabeth of Denmark, Duchess of Mecklenburg