John Jacob, Marquess of Montferrat Marquess of Montferrat (1395–1445) Parents Jeanne of Bar Theodore II, Marquess of Montferrat Children Amadea Palaiologina of Montferrat William VIII, Marquess of Montferrat John IV, Marquess of Montferrat Isabella Palaiologina of Montferrat Boniface III Teodoro Paleologo di Montferrato Siblings Sophia of Montferrat Partners Joan of Savoy