Born June 7, 1938, in Koblenz, Gerlach studied law, economics, and sociology in Bonn, Cologne, Vienna, and Freiburg. He worked at Freie Universität Berlin from 1967 on, first as an academic assistant and researcher. In 1972, he became a professor of civil, commercial, and civil procedural law.

Gerlach left office prematurely, in 1999, following a severe accident.

Today, Gerlach is once again active in the field of international cooperation. His activities include serving as the president of Kazakh-German University (KGU) in Almaty, Kazakhstan, and memberships in the Board of the German Academic Exchange Service (DAAD), the International Committee of the German Rectors’ Conference (Hochschulrektorenkonferenz), and the steering committee of the Quality Culture Project of the European University Association.