The Blackstone Group was founded in 1985 by Peter G. Peterson and Stephen A. Schwarzman with $400,000 in seed capital. The founders named their firm "Blackstone", which was a cryptogram derived from the names of the two founders (Schwarzman and Peterson): "Schwarz" is German for "black"; "Peter", or "Petra" in Greek, means "stone" or "rock". The two founders had previously worked together at Lehman Brothers. At Lehman, Schwarzman served as head of Lehman Brothers' global mergers and acquisitions business. Prominent investment banker Roger C. Altman, another Lehman veteran, left his position as a managing director of Lehman Brothers to join Peterson and Schwarzman at Blackstone in 1987, but left in 1992 to join the Clinton Administration as Deputy Treasury Secretary.