When Ken Costa joined Lazard in late 2007, the late Bruce Wasserstein, then chairman and chief executive, said that Costa embodied "the special character of Lazard". Three and a half years on, the committed Christian and Conservative party benefactor has taken his leave from the independent adviser.

A former student of philosophy and law at the University of the Witwatersrand, Johannesburg, Costa was active in the student protest movements against apartheid, and later considered becoming a priest.