By November 1942, Coulaudon was head of
Combat in Puy-de-Dôme. In April 1943, he went into hiding and created the Auvergne 1st Corps Franc, whose command post was situated in the hamlet of Lespinasse, in the commune of
Pulvérières. He led this group in numerous acts of sabotage (including
Ancizes steel mill, a German transmitter at
Royat, a train carrying German troops at Martres de Veyre) and rescued numerous Resistance fighters. His acts also enabled the recovery from
Vichyist stores of over 200,000 litres of petrol, 100 tonnes of food and clothing (from the
Chantiers de la jeunesse française youth organisation at
Chatelguyon), and 150 vehicles of different kinds, While looking for the command centre of the
Mouvements unis de la Résistance in Puy-de-Dôme on 11 December 1943, the
Sicherheitsdienst launched an offensive at
Saint Maurice. Coulaudon, Antoine Llorca ("Laurent") and the main local Resistance members fled, but the next day the Sicherheitsdienst found a briefcase containing important documents, which it had not been possible to dispose of. The next day, at
Billom, Gaspard and his comrades ("Laurent", Robert "Prince" Huguet, Max "Bénevol" Menut, Camille "Buron" Leclanché), narrowly evaded a search party led by Hugo Geissler, comprising 2,000 soldiers from the 66th Army Reserve Corps. In the following days, Resistance munitions and supplies were seized. On 15 April 1944 at
Montluçon, Coulaudon met
Maurice Southgate, an
SOE agent known as Major Philippe, head of the Hector-Stationer Resistance network. They discussed creating a Resistance hideout in Auvergne. This was based on an idea of the official French army and General Georges Revers, of the
Organisation de résistance de l'armée, of whom Gaspard had a vague awareness. Southgate organised a mission, Operation Benjoin, which involved parachuting in light and medium arms including machine-guns, anti-tank rocket launchers and light artillery. Despite Southgate's arrest in May, the
maquis welcomed the participants in an SOE operation codenamed Freelance, Captain
John Hind Farmer ("Hubert"), Captain
Denis Rake ("Justin") and the Australian Lieutenant
Nancy Wake ("Hélène"), then those of Operation Benjoin, led by British major Freddy Cardozo. In spring 1944, Coulaudon became head of the ''Forces françaises de l'intérieur
in the Clermont region, comprising four départements'':
Puy-de-Dôme, Haute-Loire,
Cantal and
Allier. As a member of the Regional Liberation Committee, he took part on 2 May in the General Meeting of the Auverge Resistance, chaired by Henry Ingrand at Boitout farm, a few kilometres from
Paulhaguet. He proposed three hideouts: one at
Mont Mouchet, one in the
Truyère valley and one at
Le Lioran. The proposal was approved and it was decided to create two
divisions, one political and one military. After repelling an initial attack on 2 June, on 10 June, the 2,700 maquisards at Mont Mouchet were attacked by elements of two German columns from
Brioude,
Saugues and
Saint-Flour, under the command of Kurt Jesser. The resistants fought hard and managed to escape the hideout, and the same happened at La Truyère. After that, they carried out an intensive campaign of ambush and sabotage. The activity of ''Forces françaises de l'intérieur'' in
Massif Central, including those in the Auvergne led by Coulaudon, led to the pinning-down of 2,000 German soldiers in the region, who surrendered at
Decize,
Nièvre, on 11 September 1944. == Post-war ==