James Gillray

Often called the father of editorial cartooning, and the place to start. Gillray's Georgian London prints set the template: grotesque, crowded with funny details, yet built on properly drawn anatomy. His targets were the biggest names of the age. George III squints at a portrait of Cromwell, Fox flogs Pitt the Younger, and Napoleon becomes a tiny man in a preposterously large hat, cutting up the world. That little-Corsican image outlived both men. Napoleon is reported to have said the prints did him more damage than a dozen generals, which may be legend, but it tells you how seriously they were taken.