Cornelis van der Zwalm was originally a boat worker and learned to paint at the evening academy in Rotterdam. As the subject of his paintings and drawings, he chose what was close to his heart: ships and harbour views in and around Rotterdam. He was a rough lump, a 'loner', who did not participate in exhibitions and did not join a painters' association. That is why he has remained relatively unknown to the general public. The Scheepvaartmuseum Rotterdam owns drawings by him.