The two painters produced this portrait to commemorate their youngest brother, Moses, who was born in 1645. Moses died in 1667 during the storming of Fort Languard near Felixstowe in England. He had served in the Dutch navy against the English since 1664. In the painting Moses is surrounded by symbols that allude to his military life: time (the pocket watch), death (the skull), eternity (the ivy on the rocks) and loyalty (the dogs).