Larminat joined the French Army at the outbreak of the First World War as a private and by 1915 had completed his officer training and later fought at the Battle of Verdun.

Completing his military studies at Saint-Cyr in October 1919, Larminat volunteered to serve in the colonial infantry.

De Larminat is held responsible for the controversial bombardment and destruction of the French city of Royan in January 1945.

[1] After the war, Larminat served in several positions, notably as the Inspector-General of overseas troops and the inspector of colonial forces.

Larminat retired to the reserves in 1956 and was briefly recalled to active duty in 1962 to chair the Court of Military Justice charged with judging the actions of French officers who took part in the rebellion of colonial troops in Algeria in 1961.