Beginning on the night of 23 March 1945, Operation Plunder was the crossing of the River Rhine at Rees, Wesel, and south of the Lippe River by the British Second Army, under Lieutenant-General Miles C. Dempsey (Operations Turnscrew, Widgeon, and Torchlight), and the United States Ninth Army (Operation Flashpoint), under Lieutenant General William H. Simpson. The U.S. XVIII Airborne Corps, consisting of the British 6th and U.S. 17th Airborne Divisions, conducted Operation Varsity, airborne landings on the east bank in support of Operation Plunder. All of these formations were part of the 21st Army Group under Field Marshal Bernard Montgomery. This was part of a coordinated set of Rhine crossings.