The style of Decamps was characteristically and intensely French. It was marked by vivid dramatic conception, by a manipulation bold and rapid, sometimes even to roughness, and especially by original and startling use of decided contrasts of colour and of light and shade. His subjects embraced an unusually wide range. He availed himself of his travels in the East in dealing with scenes from Scripture history, which he was probably the first of European painters to represent with their true and natural local background. Of this class were his Joseph sold by his Brethren, Moses taken from the Nile, and his scenes from the life of Samson., nine vigorous sketches in charcoal and white. Perhaps the most impressive of his historical pictures is his Defeat of the Cimbri, representing with wonderful skill the conflict between a horde of barbarians and a disciplined army.
Decamps produced a number of genre pictures, chiefly of scenes from French and Algerine domestic life, the most marked feature of which is humour. The same characteristic attaches to most of his numerous animal paintings. He painted dogs, horses, & c., with great fidelity and sympathy; but his favourite subject was monkeys, which he depicted in various studies and sketches with a grotesque humour that could scarcely be surpassed. Probably the best known of all his works is The Monkey Connoisseurs, a clever satire of the jury of the French Academy of Painting, which had rejected several of his earlier works on account of their divergence from any known standard. [...]
Source: Entry on the artist in the 1911 Edition Encyclopedia.