Theodore I Palaiologos

Theodore I Palaiologos (c. 1290–1338) was Marquis of Montferrat from 1306 and founder of its Palaiologan line. The second son of Emperor Andronikos II and Irene of Montferrat, he was born in Constantinople as a porphyrogennetos. When his uncle John I, last of the Aleramici marquises, died heirless in 1305, the march passed to Irene's children.

The patriarch of Constantinople blocked the claim of Theodore's elder brother John, so Theodore sailed to Genoa in 1306 and in 1307 married Argentina Spinola. Manfred IV of Saluzzo had occupied much of the march, and other rivals also wanted a share.

Backed by the Spinola and local supporters, Theodore won back the lost lands within a few years and in 1310 received investiture from Henry VII. He died in 1338, succeeded by his son John II.