While the flank companies were engaged in this service, the regiment was stationed at Wallajahbad, from whence it marched, in August, to St. Thomas's Mount, and in September to Madras, where it embarked on board the "Russell," of seventy-four guns, and the "Cornwallis," "Hesper," "Cornelia," "Bucephalus," and "Clorinde" frigates, to take part in the expedition against the _Mauritius_, or _Isle of France_, another island in the Indian sea, belonging to France; the grenadiers and light infantry of the regiment also embarked from St. Paul's in the island of Bourbon, to share in the enterprise. On the 28th of November the armament approached the Isle of France, and the troops effected a landing in the bay of Mapon, when one brigade was ordered into a large wood, through which it was necessary to pass. The light company of the TWELFTH under Captain Forssteen, preceded by a section under Lieutenant Ashe, penetrated among the trees, and skirmished with a French piquet, in which service two men were killed, and Lieutenant Ashe and three private soldiers wounded. After a march of nine miles, the light infantry of the TWELFTH halted on some low ground surrounded by jungle. The weather was very hot, water could not be procured, and the sufferings of the soldiers, in consequence, were very severe; but on the following day some alleviation of suffering was obtained by sucking the dew from the herbage, and advancing to the powder mills, within five miles of Port Louis, the capital, clear streams of water were discovered. While halting at this place, the piquets were attacked by the enemy, when the rifle company of the TWELFTH, and the light infantry of the fifty-ninth, dashed forward, and drove back the French skirmishers, wounding General de Caen. On the following morning the army advanced, the grenadiers of the TWELFTH being in front, and the light infantry on the flanks, under Captains Firth and Forssteen, Lieutenant Keappock commanding the leading section of grenadiers. While advancing along a narrow road, through a country covered with underwood, the army was suddenly assailed with grape shot, from an eminence; but a charge with bayonets forced the French to withdraw. Arriving at some open grounds, the British formed line, when the French abandoned their guns and retreated towards the town, leaving a body of troops on a mountain on the British left. The TWELFTH were ordered to storm the height, and they raised a loud shout, and soon gained the summit, when the French fled, leaving a gun behind them. The officers and soldiers of the regiment evinced great heroism in these services; Lieutenant Keappock was wounded in the side, but continued at his post until a shot in the head forced him to retire; his honourable, though dangerous post, was taken by Lieutenant Jenkins, who received a severe contusion on the breast by a ball, but continued at the head of the leading section.