 Fellow members whom he came across at this time included Friedrich Wolf, Harro Schulze-Boysen, Heinrich, Count von Einsiedel and the group's founder, Eberhard Koebel.Between 1931 and 1935 Gerstner studied Jurisprudence at Berlin's Frederick-William University (as the Humboldt was then known).As a student he funded his living costs by working part-time at the foreign-exchange desk of the Deutsche Bank.