World War I It belonged to
6th Army Corps and had its headquarters at the
Reims garrison as of 1 August 1914 and was mobilised in the 6th Region. Between 1 and 14 August it was taken by train to
Vigneulles-lès-Hattonchâtel and ordered to defend the region around
Heudicourt and
Thillot. From 14 August it began to move a position near
Fresnes-en-Woëvre, then near
Etain. It went on the offensive towards
Chiers on 21 August as part of the
Battle of the Ardennes and the following day fought its way towards
Ugny and
Doncourt-lès-Longuyon, followed by fighting on the
Crusnes and near the farm at
Puiseaux and near
Rèvemont on 23rd and near
Arrancy on the 24th. On 25 August it withdrew to the west towards the
River Meuse and new positions near
Damvillers and
Consenvoye. From 27 August it defended the river crossings around
Gercourt and
Brieulles-sur-Meuse and from 2 September resumed its withdrawal, this time south towards
Montfaucon,
Jubécourt and finally
Rembercourt-aux-Pots. There it took part in the
First Battle of the Marne from 6 to 20 September, including around
Sommaisne and
Rembercourt-aux-Pots during the
battle of Revigny - one of the German officers attacking it was
Erwin Rommel. On 14 September it began to be pursued towards
Nixéville and
Charny before it was able to hold its position around
Ville-devant-Chaumont in bois d'Haumont. On 20 September it was taken out of the front-line and moved to
Mouilly and
Rupt-en-Woëvre. From 21 September it manned the front in the
Braquis region opposite
Étain until being urgently ordered to the trenches at Calonne to stop the German offensive. It marched towards
Saint-Mihiel and the Hauts de Meuse and on 22 September arrived at Rupt in Woêvre and fought at
Mouilly, the Calonne trench,
Saint-Remy, positions in
Les Éparges and in front of the Calonne trench-line. The front then stabilised and it was placed in a sector around the bois Loclont and
Trésauvaux. It made an attack on the Calonne trench on 26 December. From 17 to 21 February 1915 it was involved in fierce fighting during the
battle of Les Éparges, where it was also engaged resumed on 18th, 19 and 27 March. On 18–20 March it carried out a joint attack on
Verdun with the Marche Infantry Division, originally planned for 10–11 March. 12th Division was ordered to capture two bastions to its west and east, joined by a trench - the trench and eastern bastion formed two intersecting lines of fire, whilst the western bastion formed three, all reinforced with underground bunkers. The French would attack from part of a spur taken in previous attacks, 50 metres away from the German positions. The explosion of mines made little effect, as did a 45-minute bombardment from 15:15 hours on 18 March.
132nd Line Infantry Regiment led the attack at 16:05, taking spur C fifteen minutes later but the German response meant the attack was bogged down by 17:00. By 19:00 132nd Regiment had reached a mid-point between points O and X and the attack resumed at 4:45 the following morning, but was held off by German machine-gunners at point X. French artillery opened fire on the eastern point of bois des Sapins from point N at 8:30 and the attack resumed again at 9:25, but was again held off. A German counter-attack was unsuccessful at 10:00 and an hour later the line stabilised. A fresh French artillery bombardment led to new attacks at midday and 16:00, but these both proved unsuccessful. The attack resumed again on 20 March at 4:00 and by 10:00 21st Division asked 24th Brigade to organise its positions.
Second World War On the declaration of war on 3 September 1939 the division at
Thionville in northern France and was placed on the border opposite the German troops advancing towards
Kœnigsmacker near the end of the
Maginot Line. After a month of fighting it was relieved and went into reserve near
Hirson. On 10 May 1940 the division was attached to
5th Army Corps, which formed part of
1st Army. Most of the division was sent to the
Saint-Quentin area on that date, although 3e GRDI were stationed to the south of
Maubeuge in accordance with the
Dyle Plan,
Plan Yellow and the order to occupy the
Gembloux sector near
Namur. 3e GRDI and the engineers of 2nd Engineer Regiment were soon moved to fight delaying actions in advance of the defensive positions between
Rhisnes and
Temploux. On the night of 10–11 May reconnaissance parties from these detachments advanced into Belgium and from 18:00 took up positions to the rear of the Cavalry Corps, which was holding the
Tirlemont-
Huy line. Meanwhile, the other elements of 12th Division set off at 17:00 to avoid the
Luftwaffe, which had already gained air superiority. On the morning of 12 May the first elements of the division arrived and its units deployed immediately into their positions, despite continued air attack in the
Dyle region, particularly at
Rhisnes and
Temploux. Ahead of the positions the engineers prepared a line of twenty demolition charges, but on 13 May air attacks became more targeted and more frequent. Rhisnes and Temploux were attacked again, as was the divisional command post at
Spy, Belgium, forcing it to move elsewhere. The infantry dug in and placed a line of anti-tank mines all along its front line, with artillery in camouflaged positions. By evening the division was the only French unit in the area which had arrived and was ready to fight. To the east the Germans had crossed the
Albert Canal, refugees were flooding west, several cut-off Belgian units were falling back and 2nd French Cavalry Corps (made up of 2nd and 3rd Light Mechanised Divisions) was preparing to fall back after fighting all day at
Hannut and
Merdorp against German tanks and
Stukas - 3e GRDI took over the liaison between these two light mechanised divisions. To the south the
9th French Army had lost several bridges over the Meuse and would have to counter-attack on 14 May alongside the powerful, armoured,
1re division cuirassée (1st Division of Cuirassers). On 14 May
Perwez was abandoned by the Belgian
Chasseurs Ardennais, who fell back behind the positions held by 12th Division. The French cavalry corps under general Prioux also withdrew, using its last tanks to protect 12th Division's engineers, enabling them to blow the demolition charges between
Hanret and
Saint-Germain and regroup at
Onoz. 3e GRDI covered the final part of the cavalry corps' withdrawal and suffered heavy losses. In the afternoon German light tanks attacked
150th Infantry Regiment's positions but rapidly withdrew under fire from
225th Artillery Regiment. At the end of the afternoon 150th Regiment's 1st Battalion and the 3e GRDI were given the order to turn south and hold the crossings of the
Sambre Sambre à
Floriffoux between
Namur and
Auvelais. From dawn on 15 May the Luftwaffe resumed its attack on the crossroads, forests and marshalling points. That morning the
8th Zouave Regiment was attacked by German tanks, who were initially sent into retreat thanks to artillery fire. However, at the end of the morning the division received the order to withdraw towards the French border. To avoid air attack it abandoned its positions at night and the division fortified a line along the Charleroi canal running through Spy,
Velaine and
Fleurus. At the end of the night 3e GRDI covered the withdrawal of 5e DINA before destroying eleven bridges between
Floreffe and
Ham-sur-Sambre and rendering one more impassible to road traffic. At dawn on 16 May the division gathered at
Orneau, where it received orders to rush to the area between
Godarville and
Motte-Courcelles on the canal to meet a German push across the Sambre to the south. At midday the division continued to withdraw, but the routes were clogged by refugees and other troops and still under constant air attack. At the end of the day the forward parties had only just reached
Gosselies and
Jumet. A detachment made up of elements of
106th Line Infantry Regiment and 3e GRDI under colonel Parent fought rearguard actions against advanced German units before retiring under cover of night. During the night of 16–17 May most of the division's infantry regiments crossed the canal via the bridges at
Roux and
Courcelles and immediately deployed. The enemy penetrated the front in force across the
Luttre bridge, which Belgian engineer units had failed to destroy, attacking and pressing 150th Regiment and 8th Zouaves, who formed the vanguard. 38e Combat Tanks Battalion and a group of reconnaissance squadrons from 3e GRDI under captain de Lannoy were given artillery support and managed to push the enemy back to the east bank of the canal. The front was re-established at 19:00, but a new order to withdraw came in and during the night of 17–18 May 12 Division took up new positions on high ground at
Bavai. After German tanks attacked at
Ciply on 19 May, the division's infantry was ordered to withdraw to Hainaut. The divisional commander had lost contact with his superior
René Altmayer and decided to withdraw again towards
Valenciennes by a night march, with 153 DIM taking up the rearguard position. On the evening of 20 May 12e DIM was switched to
3rd Army Corps and on 21 May 12 Division regrouped and headed for
Bruay-en-Artois under cover of darkness. 106th Line Infantry Regiment was detached from the division on 22 May and taken north by truck to hold a fortified position between
Cysoing and
Mouchin, while the rest of 12th Division marched on foot from
Bruay-en-Artois to
Avelin. Fighting by day and marching by night, they managed to pass through encircling German troops to finally reach
Dunkirk. Only 8,000 men of the division remained by this point and they were ordered to hold the French sector of the perimeter for nine days during the
Operation Dynamo evacuation, holding off an overwhelmingly larger German force. The division's survivors were captured on the morning of 4 June on the beach at
Malo-les-Bains.
Postwar In 1960 during the
Algerian War the division was part of the
Oran Corps Area, responsible for the West Oran Zone, with its headquarters in
Tlemcen. The division's battle honors were officially recorded and promulgated by a Defence Historical Service decision of September 2007. ==Commanders==