Sixth Crusade
In 1226, Henry's brother Louis IV, Landgrave of Thuringia, died en route to the Sixth Crusade, and Henry became regent for his under-age nephew Hermann II, Landgrave of Thuringia. He managed to expel his nephew and the boy's young mother, St. Elisabeth of Hungary, from the line of succession and ca. 1231 formally succeeded his brother as landgrave.