In 1286, the marchioness Isabella, Guy's daughter, died childless and the margraviate was immediately the subject of disputed claims: that of Thomas and that of her widower Antoine le Flamenc. Bodonitsa was a vassal of the Principality of Achaea, which was held by the bailiff William de la Roche, the duke of Athens, at the time. William, though a relative of the Pallavicini, presiding in his capacity as bailiff over the feudal court of Achaea, did not decide for Thomas as successor of Isabella before Thomas seized the castle of Bodonitsa and thus installed himself undisputedly as master of the march. He ruled it quietly for an unknown period of time, perhaps beyond 1300, and transmitted it to his son Albert.
- Miller, W. "The Marquisate of Boudonitza (1204-1414)." Journal of Hellenic Studies, Vol. 28, 1908, pp 234-249.