Theodore was a son of Emperor Andronikos II Palaiologos and Irene of Montferrat.
[1] When his uncle John I died in 1305, the male line of the Aleramici Marquises of Montferrat became extinct.
Patriarch Athanasius I of Constantinople blocked the candidacy of the elder son John, so Theodore went to Italy instead.
Theodore and Argentina had: Theodore is known to have authored an original military manual, titled Les Enseignemens ou Ordenances pour un Siegneur qui a Guerres et Grans Gouvernemens a Faire, often referred to as Les enseignements.
Originally composed in Greek in 1326-1327 while Theodore was in Constantinople, it exists now only in the medieval French translation of Jean de Vignay.