Keith Haring.

In 1980, mysterious chalk drawings of simple outline figures began appearing on unused advertising space in New York City subway stations. Combining the appeal of Disney cartoons with the sophisticated primitivism of such artists as Jean Dubuffet, these underground artworks were bold, humorous, accessible, subversive - and the work of one man - Keith Haring. Over the next decade, Haring went on to create a body of work that would capture the energy and excitement of New York's brash street culture - and transmute punk, new wave, hip-hop, graffiti and break dancing into an instantly recognizable pop iconography. He frequently bypassed the gallery scene, preferring to address people directly through drawings and paintings in public spaces and with mass-produced items based on his designs. By the time he died of AIDS in 1990 he had become New York's most celebrated artist since Andy Warhol.