The division was mobilised on 28 August 1939. Its initial composition was: • 12th Infantry Regiment (I, II, III battalions) • 17th Infantry Regiment (I, II, III battalions) • 82nd Infantry Regiment (I, II, III battalions) • 31st Artillery Regiment (I, II, III battalions) • 67th Artillery Regiment (I battalion) • 31st
Panzerjäger Battalion • 31st Reconnaissance Battalion • 31st
Pioneer Battalion • 31st
Signals Battalion • 31st Division Support Units In January 1940 the divisional replacement battalion became part of the
181st Infantry Division, and II battalion of the 12th Infantry Regiment (I/12) became part of the
295th Infantry Division and a new battalion was raised to replace it. In October 1940 roughly a third of the division was used as the core of the
131st Infantry Division, but the donated units were replaced. In 1942, II/12, II/17 and III/82 were disbanded and from this point onwards the infantry regiments of the division consisted of only two battalions each. In May 1944, the divisional fusilier battalion was formed from the divisional
reconnaissance battalion, and the division absorbed the 566th Grenadier Regiment of the 52nd Field Recruit Division which was being broken up. At this point the division comprised the following major units: • 12th Grenadier Regiment (I, III battalions) • 17th Grenadier Regiment (I, III battalions);
Oberst Wolfgang Müller, commanding officer 15 Jun 1942 – 30 September 1943 • 82nd Grenadier Regiment (I, II battalions) • 31st Divisional Fusilier Battalion (anti-aircraft) • 31st Artillery Regiment (I, II, III battalions) • 67th Artillery Regiment (I battalion) In June 1944, the division was destroyed while serving with Army Group Centre, and it was officially disbanded on 18 July 1944. On 21 July 1944, the 31st Grenadier Division was formed using a combination of the remnants of the 31st Infantry Division and a re-designation of the 550th (Sperr) Division of the 29th Wave. The major units of the division comprised: • 12th Grenadier Regiment (I, II battalions) (from the 1100th Grenadier Regiment) • 17th Grenadier Regiment (I, II battalions) (from the 1111th Grenadier Regiment) • 82nd Grenadier Regiment (I, II battalions) (from the 1112th Grenadier Regiment) • 31st Divisional Fusilier Battalion (anti-aircraft) (from 550th Divisional Fusilier Company) • 31st Artillery Regiment (I, II, III battalions) (from 1550th Artillery Regiment) • 31st Flak Company • 31st Assault Gun Battalion On 9 September 1944, the 31st Grenadier Division was re-formed as the 31st Volksgrenadier Division, and some minor re-organisation was affected. The re-organisation was completed in
Danzig on 17 January 1945. ==Commanding officers==