Professor Oskar Mahrenholtz, TU Hamburg, Germany, former President and Honorary Member of GAMM, passed away on 6th April 2020 https://www.gamm-ev.de/index.php/en/9-ueber-uns.html  The Managing Board of HSTAM and the whole community of mechanics in Greece will remember him as a good friend of us and especially initiator of the German-Greek-Polish series of conferences in mechanics