With the retirement of veteran European dealmaker Yoël Zaoui, Goldman Sachs's global mergers and acquisitions business now has a sole head: Gene Tiger Sykes, a man once dubbed the "most influential M&A banker" you've never heard of.

Sykes joined the US bank in 1984 in New York, having graduated with an MBA from the Stanford Graduate School of Business four years prior to his former co-head Zaoui.