Dutch Italianate landscape painter (also spelled Asselijn) probably a pupil of Esaias van de Velde but whose style was formed on the Arcadian landscapes of Claude, and on the Roman Campagna: hence his work resembles that of Berchem, Both and Dujardin. He spent about ten years in Italy c.1634-44. He specialized in real and imaginary scenes of the Roman Campagna, his most famous painting, however, is not a landscape, but The Threatened Swan (Rijksmuseum, Amsterdam), an unusual work - showing a bird defending its nest against a dog - that is said to be an allegory of Dutch nationalism. Rembrandt, who was Asselyn's friend etched his portrait. Because of a crippled hand he was nicknamed 'Crabbetje' (Little Crab).