Yolanda of Flanders

Yolanda of Flanders (French: Yolande de Hainault; 1175 – September 1219) was the empress of the Latin Empire in Constantinople from 1217 to 1219. Her husband, Peter II of Courtenay, was captured and imprisoned before he could reach Constantinople, so Yolanda ruled Constantinople alone. She was the margravine of Namur from 1212 until 1216.

Source: Wikipedia — https://en.wikipedia.org/wiki/Yolanda_of_Flanders