Marie de Courtenay
Marie de Courtenay (c. 1204 – September 1228) was a daughter of Peter II of Courtenay and Yolanda of Flanders. She married Theodore I of Nicaea. Marie served as regent for her younger brother Baldwin II of Courtenay and styled herself as the Empress of Constantinople.
Family and background 
Her parents were successive rulers of the Latin Empire of Constantinople. Her father was chosen as an Emperor in 1216. In 1217, while attempting to reach Constantinople by land, Peter was taken captive by Theodore Komnenos Doukas, ruler of Epirus. He spent the rest of his life in captivity. Yolanda reached Constantinople instead and took over the Empire. Marie's mother Yolanda was de jure a Regent in name of her husband but ruled alone from 1217 to 1219. Among the alliances negotiated by her was one with Theodore I Lascaris of the Empire of Nicaea. The alliance was sealed with the marriage of Theodore and Marie after Theodore repudiated his second wife Philippa of Armenia.
Empress of Nicaea 
Marie was Empress of Nicaea from 1219 to November, 1221 when Theodore died. They had no known children. One of her stepdaughters, Maria Laskarina, was the wife of the King Béla IV of Hungary, and the other, Irene Lascarina, was married to John III Doukas Vatatzes who took over the throne of the Latin Empire. Marie briefly served as a Regent of Nicaea in 1222.
Regent and Empress of Constantinople 
Her brother Robert of Courtenay had succeeded their mother in 1219. In late January, 1228, Robert himself died. Their younger brother Baldwin II of Courtenay succeeded to the throne. He was only eleven-years-old and thus underage. The barons of Constantinople elected Marie as Regent. According to "Les Capétiens" (2000) by Patrick van Kerrebrouck she styled herself Empress. Her Regency only lasted until her own death eight months later. 
- Georgius Akropolites 15, p. 29.
- Ephræmius 7715, p. 311.
- Kerrebrouck, P. Van (2000) Les Capétiens 987-1328 (Villeneuve d'Asq), p. 459.
- Her listing along with her siblings in "Medieval lands" by Charles Cawley. The project "involves extracting and analysing detailed information from primary sources, including contemporary chronicles, cartularies, necrologies and testaments."
Marie de CourtenayBorn: c. 1204 Died: 1228
Philippa of Armenia
|Empress consort of Nicaea