Because Andronikos II was eager to establish himself as legitimate in the eyes of Western Europe, he married Yolande in an effort to formally unite the claims of her family with his own de facto rule of Thessalonica, avoiding the potential future threat of a pretender launching an invasion against the empire.

In 1179, Emperor Manuel I Komnenos (r. 1143–1180) married his daughter Maria Komnene to Renier of Montferrat, who was granted the city of Thessalonica to rule as a pronoia.

Because of this family connection, Renier's brother Boniface, a leading figure in the Fourth Crusade, could claim and conquer the "Kingdom of Thessalonica" in 1204.

[1] In 1284, Yolande of Montferrat, the daughter of the ruling Marquis of Montferrat, William VII, married Emperor Andronikos II Palaiologos of the Byzantine Empire (r. 1282–1328) and was given the titles associated with Thessalonica by her father as her dowry, though it is unclear if she was meant to possess them or if she was intended to transfer them to her husband, who actually ruled Thessalonica as part of his empire.

Through marriage alliances with western pretenders to the Latin Empire, or parts of it, Andronikos would have been able to achieve full recognition of his rule in the West.

In addition to his own marriage to the pretender to Thessalonica, Andronikos also unsuccessfully attempted to marry his son, Michael IX Palaiologos, to Catherine of Courtenay, the recognized heir to the Latin Empire itself.

The marriage between Andronikos and Irene had the unexpected result of giving the Byzantine imperial family the possibility of inheriting the throne of Montferrat.

The possibility that the Italians would launch an attack on the empire as a result of the Monferrat inheritance was entertained by the Patriarch, who opposed the entire affair.

Another likely reason was that the Marquis of Saluzzo, Manfred IV, had attacked Monferrat, claiming that John I's widow, Margarita, was pregnant and that since an heir would thus be produced, a Byzantine prince was unnecessary.

Theodore converted to Catholicism and on his occasional journeys to Constantinople startled the Byzantines with his Western customs and his shaven face.

In the 1320s, Theodore was one of the most directly involved and influential figures in Andronikos II's negotiations and hopes for a union between the Orthodox and Catholic churches.

[8] Theodore founded the Palaeologus-Montferrat cadet branch of the Palaiologos dynasty,[12] fusing and subsuming the Aleramici lineage with a succession that derived from Byzantium and carried the name of the Palaiologan emperors.

[8] Although John II's claims were theoretically inherited by his descendants, none of the marquises seriously pursued a policy of taking over the Byzantine Empire, most of them paying little attention to affairs in the East.

[15] Manuel II agreed to this marriage not because they were related, but because Sophia held connections to Montferrat and Genoa, valuable allies, and because she had been suggested by the Pope.

The marriage contract between Yolande and Aymon in 1330 specified that in the event of the extinction of the Palaeologus-Montferrat line, the House of Savoy was to inherit Montferrat.

Though the then current Savoyard heir, Charles III, Duke of Savoy, made a claim to the title, the Montferrat territories were instead given to a rival contender, Federico II Gonzaga, Duke of Mantua, by Holy Roman Emperor Charles V.[19] In 1708, the House of Savoy, through Victor Amadeus II of Sardinia, succeeded in claiming Montferrat, the acquisition of which was confirmed in 1713 through the Peace of Utrecht, which ended the War of the Spanish Succession.

[29] The family tree below displays the lineage of the Paleologo in Taranto and the Montferrato-Paleologo in Cephalonia (Nicolo and his descendants), per Mallat (2007),[23] their relations to the main branch above are unclear.