Peter Paul Rubens’ “Portrait of Archduke Albrecht” (1583-1595) after it was damaged by acid while on view at the Museum of Art, Dusseldorf, in 1982. 

Hans-Joachim Bohlmann, a North German living on a disability pension since undergoing a brain operation, tossed acid at the canvas because, as he later told police, he was troubled by the figure’s piercing eyes. 

This was not Bohlmann’s first attack on an artwork: Following the death of his wife in 1977, he made a habit of vandalizing works of art, damaging a reported 23 separate paintings before being imprisoned.