[3] Following the joint German-Soviet invasion of Poland, which started World War II in September 1939, Buk was occupied by Germany until 1945.

In 1940, the occupiers carried out expulsions of Poles, who were deported to a transit camp in Łódź, while their houses and workshops were handed over to German colonists as part of the Lebensraum policy.

Tadeusz Wojtczak, founder of the local units of the Grey Ranks, was arrested by the Germans in August 1943, and following a brutal investigation he was imprisoned in the infamous Fort VII in Poznań[6] and eventually killed in the Gross-Rosen concentration camp.

[8] After the war, Buk was restored to Poland, although with a Soviet-installed communist regime, which stayed in power until the Fall of Communism in the 1980s.

In 1947, the communists arrested Henryk Blimel, leader of the local Lisy unit of the Grey Ranks, and sentenced him to 12 years in prison.