By Colonel Shee, Henry Clarke was well and carefully reared, as he intended him for the service of Louis XVI. Thus, on the 17th of September, 1781, he entered the Military School at Paris as a cadet; and after going through a brief curriculum, left it on the 11th of November, 1782, to join the regiment of the Duc de Berwick as a sub-lieutenant. Wishing to join the cavalry, on the 5th of September, 1784, he was appointed cornet of hussars, with the rank of captain in the regiment of the colonel-general of this branch of the service. On the 11th of July, 1790, he obtained a captaincy of dragoons, and in the same year received leave of absence to visit Great Britain, as a gentleman in the suite of the ambassador. It was to the friendship and patronage of the Duke of Orleans that Clarke owed these favours, and generally, his rapid advancement in the army; and it was to this prince that the hussar regiment of the colonel-general belonged, according to a custom of the old _regime_. On his return to France, Clarke applied immediately for active service, and on the 5th of February, 1792, was appointed a captain of the first class, and soon after he attained the rank of lieutenant-colonel of cavalry. He remained in command of his regiment during all the horrors of the Revolution; and, at its head, served in the two campaigns which followed the attack on the Tuileries, the deposition of the king, and the murders of 1792. In September he assisted very materially at the capture of Spire, the _ci-devant_ capital of a bishopric in the palatinate of the Rhine, along the upper circle of which Custine had spread his brilliant conquests. The French attacked the Austrians, who were in order of battle in front of the city. They were outflanked, and driven back; the gates were cut down by axes, or blown to pieces by cannon, and the republicans stormed the place, taking 3000 prisoners, with a vast train of cannon and mortars. Clarke bore a conspicuous part as an active cavalry officer in all the subsequent operations of the French army, including the capture of Worms, with all its stores, and of Mentz, before which the army arrived on the 19th of October, after forced marches, performed amid torrents of rain; and the taking of Frankfort, which was ransomed from destruction and pillage on the payment of 500,000 florins. On the 17th of March, after the rout of Bingen, he defended the passage of the Nahe, a German stream, which falls into the Rhine near the former place, and there he was of signal service to the retreating troops. He was present at the affair of Horcheim, which was afterwards annexed to France, and the capture of Landau, on the 17th of May. His distinguished bravery on these occasions obtained him the rank of General of Brigade, provisionally, the commission of which he received on the field of battle. He then received the command of three regiments of dragoons, which formed the advanced guard of the army of the Rhine.