Laussat was born in the town of Pau. After serving as receveur général des finances in Pau and Bayonne from 1784 to 1789, he was imprisoned during the Terror, but was released and recruited in the armée des Pyrénées.
Laussat was born in Pau. After serving as receveur général des finances in Pau and Bayonne from 1784 to 1789, he was detained during the Terror but was freed and recruited into the Pyrenees Army.