German Chancellor Willy Brandt fell to his knees in Warsaw

 

Brandt famously fell to his knees after adjusting the wreath ribbons at the Warsaw Ghetto memorial on December 7, 1970.

https://www.euronews.com/2020/12/07/it-s-50-years-since-willy-brandt-fell-to-his-knees-in-warsaw-to-apologise-for-nazi-era-cri?