The First Special Service Force (1SSF), sometimes referred to as the “Devil’s Brigade,” served in the European Theater from 1942 to 1944.
A combined Canadian-American unit had an impact on the development of commando units in both countries, including the US Army Special Operations Command’s 1st Special Forces Command (Airborne) and the Canadian Special Operations Regiment’s (CSOR) Canadian Special Operations Forces Command (CANSOFCOM) (USASOC). They both assert to be the First Special Service Force’s direct ancestors. Geoffrey Pyke of the British Combined Operations Command is responsible for the establishment of the First Special Service Force. In March 1942, he proposed Project Plough, which aimed to build a commando outpost on a glacier plateau in Norway.
Source: https://www.warhistoryonline.com/world-war-ii/first-special-service-force.html?safari=1
