Complex sentence: In 1647 Courtois was one of the artists who participated in the illustration of the second volume of his fellow Jesuit Famiano Strada's work, "De Bello Belgico", which is a history of the Spanish wars in Flanders in the 16th century.
Split into simpler sentences: In 1647 Courtois was one of the artists who contributed illustrations to the second volume of "De Bello Belgico", a work by his fellow Jesuit Famiano Strada's. The "De Bello Belgico" offers a history of the Spanish wars in Flanders in the 16th century.