In 1990, on the heels of the collapse of Drexel Burnham Lambert, he co-founded the private equity firm Apollo Global Management with Leon Black, Drexel's managing director, head of the Mergers & Acquisitions Group, and co-head of the Corporate Finance Department; John Hannan, Drexel's former co-director of international finance; Craig Cogut, a lawyer who worked with Drexel's high-yield division in Los Angeles; Arthur Bilger, the former head of the Drexel's corporate finance department; and Marc Rowan, Josh Harris and Michael Gross, all of whom worked under Black in the mergers and acquisitions department.