He started learning judo at the Dutch Navy , later traveling to Japan for further training . In the 1960s and 1970s , under the training of Jon Bluming , he won seven European titles , five in the +93 kg category ( 1966 – 67 , 1969 , 1971 – 72 ) and two in the open category ( 1969 and 1972 ) . He furthermore won two world titles ( 1967 and 1971 ) and two Olympic titles . His success at the 1972 Summer Olympics was overshadowed by the Munich massacre that took place days before
Munich massacre
Munich massacre
Wim Ruska