Maria of Courtenay

Her parents were successive rulers of the Latin Empire of Constantinople. Her father Peter was chosen as emperor in 1216, but in 1217, while attempting to reach Constantinople by land, he was captured by Theodore Komnenos Doukas, the ruler of Epirus, and spent the remainder of his life imprisoned.[2] Yolanda however reached Constantinople and took over the Empire. Marie's mother Yolanda was de jure regent for her husband, ruling alone from 1217 to 1219. She negotiated an alliance with Theodore I Laskaris of the Empire of Nicaea, which was sealed with the marriage of Theodore and Marie after Theodore annulled his marriage to his second wife Philippa of Armenia.[3][4]

Marie was Empress consort of Nicaea from 1219 to November 1221 when Theodore died. They had no known children. One of her stepdaughters, Maria Laskarina, became the wife of King Béla IV of Hungary, and the other, Irene Lascarina, was married to John III Doukas Vatatzes who took over the throne of the Nicaean Empire. Marie briefly served as regent of Nicaea in 1222.

Her brother Robert of Courtenay succeeded their mother in 1219. In late January 1228, Robert died and was succeeded by his younger brother, Baldwin II of Courtenay. He was only eleven years old, and thus underage. The barons of Constantinople elected Marie regent, and she styled herself "Empress", but her regency lasted only until her own death eight months later.[5]

• Lock, Peter (2013). The Franks in the Aegean: 1204-1500. Routledge.
• Ostrogorsky, George (1995). History of the Byzantine State. Translated by Hussey, Joan. Rutgers University Press.