The Light Mechanized Division was the first formation of the French army to be completely motorized. Although its initials contained the term "light", this kind of formation was even stonger than the armored divisions (DCR). This formation was named light in reference to the fact that it could deploy in combat order without any delay (and also to avoid confusion with Moroccan Divisions if this formation had been called Mechanized Division).

    This formation would not have been possible without General Flavigny who was in charge of the Cavalry from 1931 to 1936. During the 1932 maneuvers of Mailly, the Cavalry presented a mechanized security detachment which received the support of General Weygand, Commander-in-Chief of the French Army. In July 1935, the 4th Cavalry Division was to be transformed into the 1st Light Mechanized Division( since the early thirties, the 4th DC had been an experimental unit for motorization of the Cavalry).
The DLM type 1935 was to comprise:
        - a recon regiment with 2 motocyclists squadrons and 2 AMD squadrons
        - a combat brigade with 2 regiments (each with 2 AMC squadrons and 2 AMR squadrons)
        - a motorized brigade with 2 motorized dragoons regiments with 2 battalions each (one regiment was to be transported by cross-country trucks and the other one on regular trucks)
        - an artillery regiment

    The Cavalry wanted to equip its combat brigade with SOMUA S-35 tanks only but at that time, the Hotchkiss H-35 tank was used as AMC. The transformation of the 4th DC was slow and many modifications were made to the above TOE. These modifications resulted in fewer units with better equipment. The motorized brigade was reduced to one motorized dragoons regiment with 3 battalions equipped with cross-country trucks (Lorraine and Laffly). The AMR squadrons were transfered to the motorized dragoons regiment and the combat regiments were equipped with SOMUA S-35 and H-35 tanks (the slow production of the SOMUA S-35 prevented the full dotation of SOMUA S-35 in combat regiments which retained their H-35 tanks). The recon regiment has received its AMD Panhard P-178. Following his ideas, General Flavigny took command of the 1st DLM. In 1937, the 2nd DLM was created from the 5th DC and commanded by General Altmayer. The 3rd DLM would be created during the Phony War in february 1940. This DLM would mark another step in Cavalry mechanization since AMR were now replaced by Hotchkiss H-39 tanks. A 4th DLM was scheduled for summer 1940.

¹. 4th DLM was to be created on the 1st July 1940. Its elements were given between 15th-25th May to the 4th DCR, except the incomplete 7th Cuirassiers (1 squadron S and 1 squadron H) which was dispatched to the 7th Army as "De Langle's group". The 7th RDP had only two battalions and had not received any armored squadron.
². Each Regiment had:     - 1 Commanding Somua
                                       - 1 group of Somua squadrons with 2 squadrons of 23 Somua + 1 Commanding Somua
                                       - 1 group of Hotchkiss squadrons with 2 squadrons of 23 Hotchkiss + 1 Commanding Hotchkiss

    At the beginning of the war, both the 1st and 2nd DLMs were assigned to the Cavalry Corps (a Cavalry Corps without a single horse !). The Cavalry Corps was under the command of the Ist Army.The Cavalry Corps, together with the recon groups of Ist Army, was to cover the movement and establishment of Ist Army's infantry Divisions in the Gembloux Gap. In March 1940, with the 3rd DLM ready for battle, the 1st DLM was assigned to the VIIth Army, the Cavalry Corps having the 2nd and 3rd DLMs. The 1st DLM, together with the recon groups of the VIIth Army, was to cover the movement and establishment of the VIIth Army's infantry divisions between Breda in Holland and Turnhout in Belgium.

The Light Mechanized Division was built around 2 light mechanized brigades.
One of them was, in fact, an armored brigade with 2 Combat Tanks Regiments. Note that an AT squadron of 12 25mm AT guns was attached to one of the Combat Tanks Regiments.
The Other Light Mechanized Brigade had a Recon Regiment and a Motorized Dragoons Regiment with 3 battalions.
In addition to these Light Mechanized Brigades, the DLM possessed an Artillery Regiment with two groups of 12 75mm guns and a group of 12 105mm howitzers. To this Artillery Regiment were attached an AT battery of 8 47mm AT guns and an AA battery of 6 AA 25mm guns to provide defence against planes and tanks to the Artillery Groups.

The Régiment de Dragons Portés (RDP) had 3 identical battalions.

Each motorized dragoons battalion had 5 squadrons:

- 1 squadron of AutoMitrailleuse de Reconnaissance (AMR) with 1 command AMR, 4 platoons of 5 AMR each and 2 AMR in reserve. (Newly raised RDP were to receive H-39 instead of AMR35, now out of production)

- 1 squadron of motocyclists with 4 platoons. Each platoon had a command squad of 6 men (with 1 VB rifle grenadier) and two combat squads of 10 men with 2 LMGs and 1 VB rifle grenadier each, transported by 13 side-cars (one for two men). In addition to the 4 platoons, the squadron had 1 60mm mortar (4-men  crew on 2 side-cars) and a command platoon of 30 to 40 men with a few vehicules (2 trucks, 4 pick-up and 2 cars).

- 2 squadrons of riflemen with 3 combat platoons and 1 MG platoon. The combat platoon had 4 cross-country Laffly S20 TL trucks with one command squad of 7 men (with 1 VB rifle grenadier) and 3 combat squads of 10 men with 2 LMGs and 1 VB rifle grenadier each (the second LMG was affected to the truck but could be dismounted to increase the squad firepower. The MG platoon had 3 cross-country Laffly S20 TL trucks with 4 MMGs (5-men crew) and a command squad of 8 men. In addition to these platoons, the riflemen squadron had 1 60-mm mortar (7-men crew in one cross-country Laffly S20 TL truck) and a command platoon of 30 to 40 men with 5 cross-country Laffly S20 TL trucks. Therefore, each riflemen squadron had about 200 men with 21 cross-country Laffly S20 TL trucks, 18 LMGs, 12 VB rifle grenade launchers, 4 MMGs and 1 60mm mortar.¹

- 1 squadron of Mitrailleuses et Engins (support company) with 2 MG platoons, one mortar platoon and one anti-tank platoon. The MG platoon was its riflemen squadron's counterpart with 3 trucks and 4 MMGs each. The mortar platoon had 5 trucks with one command squad and 2 groups of 2  81mm mortars with 7-men crews each. The anti-tank platoon had 2 groups of 2 trucks with one 25mm AT gun (8-men crew). The anti-tank platoon also had 4 more trucks and 2 pick-up. In addition to these platoons, the support squadron should have a command  platoon with 4 more trucks. Therefore, the support squadron had 19 trucks, 8 MMGs, 4 81-mm mortars and 4 25mm AT guns.

The Motorized Dragoons Battalion (DLM type) was a powerful unit that would prove to be a real match for the Schutzen battalions of the Panzer Divisions.

¹ The 1st DLM was equipped with Lorraine 28 instead of Laffly S20 TL trucks

The Régiment de Combat (RC) had  4 squadrons:

- 2 squadrons of Light Hochtkiss tanks with 1 command H-35/39 tank, 4 platoons of 5 H-35/39 tanks each and 2 H-35/39 tanks in reserve.¹

- 2 squadrons of Medium SOMUA tanks with 1 command S-35 tank, 4 platoons of 5 S-35 tanks each and 2 S-35 tanks in reserve.

The regiment was organized into 1 group of Hochtkiss squadrons and 1 group of SOMUA squadrons. The commander of each group had 1 command tank.
In addtion, the Regiment commander also had 1 command S-35 tank.

¹ In each Hotchkiss platoon, the platoon leader received a tank with the new APX-R1 turret armed with the 37mm SA38 (a 37mm gun of 34 calibres) instead of the APX-R turret armed with the 37mm SA18 gun (a 37mm gun of 20 calibres)
 

Tanks Transmission

    In 1940, only the platoon leaders had received radios. The ER29 radio had a theoretical range of 5 km. This radio had a different frequency than the infnatry ER40 radios which equipped the motorized dragoons and artillery units of the DLM. Contrary to the SOMUA S-35, the Hotchkiss tanks had not been built to have an internal radio. Therefore, the ER29 radio had to be put into an armored box at the rear of the Hotchkiss tank. In the SOMUA S-35, the ER29 radio was directly operated by the tank leader freeing the radioman who could help loading the 47mm gun. The remaining SOMUA S-35 of the platoon were to be equipped with an ER28 radio, but this was not done before the end of the Western campaign. Combat experience in the SOMUA S-35 would reveal that the operating box of the ER29 radio in turret was in the ejection  path of the 47mm rounds. Therefore, after firing their first round, platoon leaders would have a very big surprise !

The Régiment de Découverte (RD) had  4 squadrons:

- 2 squadrons of AutoMitrailleuses de Découverte (AMD) with 1 command AMD, 4 platoons of 5 AMDs each and 2 AMDs in reserve.

- 2 squadrons of motocyclists with 4 platoons each. Each platoon had a command squad of 6 men (with 1 VB rifle grenadier) and two combat squads of 10 men with 2 LMGs and 1 VB rifle grenadier each, transported by 13 side-cars (one for two men). In addition to the 4 platoons, the squadron had 1 60mm mortar (4-men  crew on 2 side-cars) and a command platoon of 30 to 40 men with a few vehicules (2 trucks, 4 pick-up and 2 cars).

The regiment was organized into 2 groups comprising each 1 AMD squadron and 1 motocyclists squadron. The commander of each group had 1 command AMD.

¹ . The 1st, 2nd and 3rd DLM were rebuilt with various elements from Dunkirk
² . The 4th DLM was built from the remmants of 1st DLC, 17th GRCA and 2nd GRDI
³ . The 7th DLM was built from the remmants of the 4th DLC

    Everything that could be gathered from factories and training schools was put together to try to rebuilt mechanized formations to be employed in counterattacks for the Weygand line along the Somme and the Aisne rivers.The first 3 DLMs were rebuilt on a mini DLM basis with:
        - 1 recon regiment with 2 motocyclist squadrons and 1 AMD platoon (5 AMD P-178)
        - 1 tank regiment with 1 SOMUA squadron (with 12 tanks) and 1 H-39 squadron (with 12 tanks)
        - 1 Motorized Dragoon Regiment with 1 battalion (two from June 13th) probably without AMR squadron
        - 1 group of 4 75mm guns, 1 47mm AT gun battery and 1 25mm AA gun battery.
    In fact, the 3 June DLMs were still weaker than a May DLM. Each DLM was roughly stronger than a motorized recon battalion (GRDIm). They were equipped with new american trucks and american sidecars.

    The other two DLMs, created from remmants of Light Cavalry Divisions, were a little bit stronger with a much stronger artillery support from their original divisions. In both divisions, one of the cavalry regiment was transformed into a motorized dragoon regiment (the other cavalry regiment was probably disbanded and used as reinforcement for the original motorized dragoon regiment). We can probably assumed that each motorized dragoon regiment was now only 1 battalion strong.

    In addition to the above rebuilt DLMs, De Langle de Cary's battle group can also be viewed as a mini DLM: it consisted of 7th Cuirassiers (with still about 25 SOMUA S-35 and 35 H-39 with the long 37mm gun), the 3rd battalion of the 7th RDP (no AMR) and the 54th Artillery Battery with 5 Laffly W15TCC tank destroyers and 3 25mm AA guns. This unit was to act as a reserve for the Xth Army on the Somme river.