According to Felibien, a scholar and close friend of Louis du Guernier, his grandfather was apparently "a man trusted with matters of importance in the Parliament of Rouen", but he lost all his possessions in the Wars of Religion.

His son, Alexander I, had fled to England and when he returned to France, the need to support his family forced him to start working as a painter of miniatures. He married Marie Dauphin, who was the daughter of a painter in Troyes, but he died young, leaving several children in great financial need. The eldest, Louis, became the head of the family and started to work as a painter of miniatures as his father had done before him. Among the other children, several took up the same career : they were at the frontier between craftsman and artist.

• Pierre was born in 1614, accepted by the Royal Academy of Painting and Sculpture in 1633 and was admitted as a painter of miniatures. He was buried on 27^th October 1674 in the Saints-Pères churchyard.
• Alexander II was employed by the king as a painter. He was buried in the Saints-Pères churchyardon 22^nd September 1665.
• Suzanne was especially good at drawing ; she married Nicolas Colsonnet, an engineer. On his death she married the painter Sébastien Bourdon on 13^th January 1641 in the church at Charenton. She died in September 1658 and was buried in the Saints-Pères churchyard.