In the years in the run up to WW2, Royal Dutch Shell was a business partner both Internationally and in Germany with IG Farben, the notorious German chemical firm. Farben supplied Zyklon-B gas to the Nazi concentration camps, in which millions of innocent people including children, were murdered in the Holocaust.
IG Farben shared patent rights to synthetic oil and other products with Shell.
Royal Dutch Shell group was also a major partner with Farben in jointly owned companies, including Deutsche Gasolin A.G., which operated a refinery and gasoline service station network in Nazi Germany.