"He attacked powerful people in a most ferocious way, with brilliant draughtsmanship. Gillray opened the whole thing up. I share his scatological humour and obsession with movements of the body. Gillray also seemed to notice every wrinkle and crease – he's equally good at extremes of girth and thinness. I love Pitt as Death on a Pale Horse in Presages of the Millenium, galloping over the "swinish" advocates of peace with France, because it's so wild. I once drew Mrs Thatcher as the top bitch at Cruft's, with Heath as a tiny turd on the ground beside her."