In 1647 Jacques Courtois married in Rome Anna Maria Vaiani, a daughter of the Florentine painter Alessandro Vaiani, and a painter and engraver in her own right. His wife was already in her forties when she got married. The marriage was not successful and the couple soon separated for unknown reasons. When Courtois left Rome for Siena she did not follow him. Courtois was called to enter the service of Prince Mattias de' Medici, the then governor of Siena and brother of Ferdinando II de' Medici, Grand Duke of Tuscany. The Prince unsuccessfully tried to reconcile the spouses. The couple did not reunite when Courtois returned to Rome later that year.