Mary married Otto IV of Brunswick, Holy Roman Emperor after 19 May 1214 in Maastricht. Otto (son of Henry the Lion of Saxony, Duke of Saxony and Bavaria and Matilda (Maud) Plantagenet) was born about 1183; died on 19 May 1218. [Group Sheet] [Family Chart]
Family/Spouse: William I of Holland, Count of Holland. William (son of Floris III of Holland, Count of Holland and Ada of Huntingdon, Countess of Holland) was born about 1167 in The Hague, Netherlands; died on 4 Feb 1222. [Group Sheet] [Family Chart]
Abt 1191 - Aft 1260 (69 years)
