With nineteen galleries that bear his name, from New York to London to Athens to Hong Kong, generating more than a billion dollars in annual revenue, Gagosian may well be the biggest art dealer in the history of the world. The most powerful figure on the contemporary art scene, Gagosian represents A-list artists like Jeff Koons, Damien Hirst, John Currin, and Richard Serra along with Jenny Saville, Anselm Kiefer, Cy Twombly, Donald Judd. He attended U.C.L.A., where he studied English, joined the swim team, and did a little photography. But he dropped out twice and took six years to graduate in 1969. There was a brief, ill-considered marriage, in Vegas, to a college girlfriend, Gwyn Ellen Garside. In 1985, Gagosian relocated to New York City and opened a gallery on Twenty-third Street, in Chelsea. He built a base of top-tier clients. His gallery is now headquartered in the Parke-Bernet building, and now takes up two whole floors. There’s a retail shop on the ground floor, which sells art books, prints, and T-shirts.