On July 10, 1767, Gabriel entered the army, joining the Marquis of Lambert’s regiment.  The young volunteer, who was now eighteen, behaved well, and speedily gave evidence of the military talents he afterwards displayed.  But a quarrel arose over a love affair, which led to harsh punishment by his colonel.  The incident was bitterly resented by his father, who condemned him without hearing his side of the matter, and actually procured his imprisonment in the fortress of the Isle of Rhe.

When the young soldier came out of prison he unwittingly offended an officer at Rochelle, who had been dismissed the service.  The result was a duel, in which the aggressor was wounded.  Gabriel was appointed to service in Corsica, with the rank of second-lieutenant, and here he distinguished himself by his zeal, his military talents, and his constant application.

Young Mirabeau was, in September, 1770, transferred to Limousin, in west Central France.  Such was his energy that he was called “the hurricane.”  Now began a series of troubles caused by bitter quarrels between his parents, who were openly at variance.  Each sought to gain an adherent in their son, who was condemned to witness the wickedness and folly of both in their ungovernable passion.  The effect on the character of the young count was deplorable.

Then ensued a singular episode.  The marquis had determined that Gabriel should marry before the age of twenty-three, and had fixed on Mary Emily de Covet, only daughter of the Marquis de Marignane, eighteen years of age, for his son’s bride.  She was plain, yet attractive, with a sweet smile, fine eyes, and beautiful hair, and was gay, lively, sensible, mild, and very amiable.  Having been neglected by her father and ill-treated by her mother, she showed no disinclination to marriage, and in 1772 young Mirabeau obtained the hand of the wealthy heiress.

No sooner was the young count married than every attempt was made to ruin him.  He received no property with his bride, and his avaricious father refused to advance him any money for necessary expenses.  His father-in-law offered to lend him 60,000 livres, but his father’s consent was indispensable, and this was sternly refused.  Mirabeau, harassed by creditors, was dragged into lawsuits, and his embarrassments only set his father entirely against him.  The marquis actually procured a lettre de cachet, obliging his son to leave the home he had set up, and to confine himself to the little town of Manosque.

Here domestic sorrow and the most painful circumstances assailed the young exile.  But these did not prevent him from pursuing serious studies and composing his first work, the “Essay on Despotism.”  Misfortunes accumulated.  Chastising with a horsewhip a baron who grossly insulted him, the count was again imprisoned, this time in the Chateau d’If, a gloomy citadel on a barren rock near Marseilles.