In 1639 he was invited to become a musician at the court in Brussels, and two years later he had his portrait painted by Gerard Seghers.
In August 1684 Saint-Luc was still living in Brussels, but nothing is known of his whereabouts during the next 16 years: the next mention of him is from 1700, when he visited Berlin on the occasion of the marriage of Prince Frederick of Hesse-Cassel and Princess Louise Dorothea of Prussia.
He apparently traveled to Berlin from Vienna, where, according to contemporary sources, he was employed by Prince Eugene of Savoy.
Saint-Luc was still alive in 1707 and 1708, when he published some of his compositions in Amsterdam; his date of death is unknown.
And indeed, the booklet to a CD issued in 2018 (by Evangelina Mascardi, http://www.musiqueenwallonie.be/, booklet text obviously not available online) proposes that some of the music attributed to Jacques was in fact composed by his son Laurent (born and baptised in Brussels in 1669).