Margaret, Marchioness of Namur

Margaret of Courtenay (1194–1270) was the daughter of Peter II of Courtenay, Latin Emperor of Constantinople. In 1217 she married Henry I, Count of Vianden. When her brother Henry II died in 1229, she seized Namur and defended it against Ferrand of Flanders until 1232.

She ruled the margraviate until 1237, when her brother Baldwin II reclaimed it and she withdrew to Vianden. Widowed in 1252, she became a nun at Marienthal, dying on 17 July 1270. Her children included Philip, Count of Vianden, and Henry, bishop of Utrecht.