Johann I Duke of MECKLENBURG SCHWERIN
He married Katharine Princess of Saxony-Lauenburg-Ratzeburg 1416 . Katharine Princess of Saxony-Lauenburg-Ratzeburg was born at of Ratzeburg, Schleswig-Holstein, Prussia Abt 1380 daughter of Erich IV, Duke of Saxony Lauenburg Ratzeburg and Sofie Princess of Brunswick .
They were the parents of 2
children:
Heinrich II "the Fat" Duke of Mecklenburg Schwerin
born 1417.
Johann II Duke of Mecklenburg
born 1418.
Johann I Duke of Mecklenburg Schwerin died 16 Oct 1422 at Schwerin, Mecklenburg-Schwerin, Germany .
Katharine Princess of Saxony-Lauenburg-Ratzeburg died Aft 18 Nov 1448 .