E.P. Cherenkova

A. I. Lebedev

P. S. Baranov

P. A. Cherenkov, the discoverer of the Cherenkov radiation, played a key role in the development of research collaboration between FIAN in Moscow and DESY (Deutsches Elektronen-SYnchrotron) in Hamburg. This article describes the history of that international collaboration during the late Soviet period, obstacles that had to be overcome, and main achievements. The idea initially came from a meeting in 1983 and led to FIAN's participation in the development of and experiments on HERA, DESY's electron-positron collider constructed between 1984 and 1991. In particular, FIAN contributed a 2000 ton magnet for the detector HI.