Born in Burgundy in 1621, Courtois moved to Italy around 1636. He learned his trade initially together with his brother Giacomo from their father Jean-Pierre, a modest painter. While both were known for their battle scenes, Jacques was able to improve his technique by painting military episodes and landscapes from life during his stay in Milan, where he was hired by the Spanish troops. His numerous travels in Italy took him from Milan to Bologna, Venice, Florence, Siena and finally Rome, where he arrived in 1640 and attended the school of Pietro da Cortona. It was there that he met Michelangelo Cerquozzi, known as Michelangelo delle Battaglie for his battle scenes, and the Dutchman Pieter van Laer, known as Bamboccio, who introduced him to the “bambocciante” style of painting in fashion during that period. It was also in Rome that he obtained his first official commission at the monastery of Santa Croce in Gerusalemme, where he painted the ceiling of the refectory and where he was to die in 1676.