, which was co-designed by Le Marchant Le Marchant served as a
brigade major during the disastrous
Flanders campaign, and for a time held command of his regiment as the most senior officer present. His practical experience in the field brought to Le Marchant's attention the many deficiencies of equipment and training the British cavalry suffered from. He was impressed by the Austrian cavalry who were operating alongside the British, and was particularly struck by the disparaging remark of an Austrian officer who thought that the British cavalry's swordsmanship was "most entertaining" but reminded him of "someone chopping wood". On his return to Britain he exerted himself to improve the equipment and combat training of the British cavalry. In 1795-6 he designed, in collaboration with the Birmingham sword cutler Henry Osborn, the
Pattern 1796 light cavalry sabre, which was adopted for British light cavalry units. In 1796 his treatise of instruction in mounted swordsmanship was adopted by the army as part of its official regulations,
The Rules and Regulations of the Sword Exercise of the Cavalry. The sword exercise became quite celebrated, and the elderly
King George III became familiar with it, and country lanes abounded with small boys practising the cuts with sticks. Le Marchant toured Britain teaching cadres, drawn from both regular and
yeomanry cavalry units, his system of swordsmanship; his methods were practical and painstaking and he was himself a superb mounted swordsman. Le Marchant was also to have gone to Ireland to teach his sword exercise there but was prevented from doing so, so his brother-in-law, Lieutenant Peter Carey of
16th Light Dragoons, undertook this duty in his stead. Le Marchant was promoted to
lieutenant colonel in 1797. His promotion was at the direct behest of the King (Le Marchant lacked the family influence and wealth which was normally necessary for advances in rank), with whom Le Marchant had developed a friendly relationship. George III is reported as saying to Le Marchant "I dare say many persons will claim the merit of your promotion; now I wish you to know that whatever merit there is in it rests entirely between you and me, for no one else is concerned in it".. After his promotion he served as second-in-command of the
7th Light Dragoons which
Lord Paget commanded. Paget, as the Earl of Uxbridge, was later to command the Anglo-allied cavalry at the
Battle of Waterloo. Though a good relationship existed between himself and Paget, Le Marchant found it difficult to keep company with the immensely wealthy and fashionable peer. He therefore transferred to his old regiment, the 2nd Dragoon Guards, becoming the regiment's commander. ==Founder of the first British military college==