His drawing abilities were observed by François van der Donckt, a local portrait painter who took him in, gave him his first lessons and helped him enroll at the art academy.
Not long after, Suvée went to Rome to become Director of the French Academy, but Gregorius was able to find a position in the studios of Jacques-Louis David.
In 1805, he was back in Bruges, making preparations to enter the Prix de Rome, but fell ill and was unable to participate.
In addition to the usual French nobility, he is also known for his portrait of August Wilhelm Schlegel, which is now on display at Coppet Castle.
He served until 1852, when he was forced to resign after clashes with colleagues, students and city officials over his conservative approach to art.