The Dauphin's Cavalry Regiment () was a line, later heavy cavalry regiment of the French Royal Army, and the last of its type to be formed by the time of the French Revolution. Formed in 1668, the Dauphin's Cavalry would see service in multiple conflicts, notably the War of the Spanish Succession, Austrian Succession, and Seven Years' War. However, following the French Revolution, the regiment was transformed into a heavy cavalry regiment, and later a cuirassier regiment which ended the royalist lineage of the regiment. After a brief reformation in 1814, the regiment was once again recreated in 1815 after the Bourbon restoration. The regiment then limited action during the Spanish Expedition, and was finally disbanded in 1830 following that year's Revolution. The regiment's successor, the 12th Cuirassiers would serve notably in the Revolution and Republican periods and continues to serve today as an armoured regiment.
War of Devolution
The formation of the Dauphin's Cavalry Regiment is rather obscure, as at the time of formation, two separate groups and dauphins were present in France. According to some sources, the regiment was formed by merger of various independent cavalry companies and one company of the Dauphin's Light Cavalry (Chevaulégérs du Dauphin).
In 1667, following the French law signed by Louis XIV entitled Jus Devloutionis, a large part of the Spanish Netherlands and Franche-Comté was to be recognised as his, thereby being part of France. However, following a short war in 1667 and 1668, the Kingdom of France came out victorious and in the Treaty of Aix-la-Chapelle, these regions, were ceded to France. However, before the cessation of hostilities, a new regiment of horse was being raised within the region, and was handed over to Louis de Bourbon, Dauphin of France, heir to the French throne. The reason for this appointment seems to be unknown, either because he was spontaneously chosen for this operation, or as a good courtier he had requested this favour. The new regiment, affectionately known as the Dauphin's Regiment of Light Horse (Régiment des Chevaulégers du Dauphin) was under command of the dauphin's sister, Louise, Mademoiselle de La Vallière, who already raised and oversaw the new unit for a short period.
Training for the new regiment took place in La Bassée in the Province of Flanders, where it was expanded to the size of a full regiment, and no longer that of a company. Here, the regiment was joined by one of the Companies of Ordnance belonging to the Dauphin, and soon eight other companies from other regiments. It was at this point that the Dauphin handed over operational control to the Marquis de Cornelius. Following the treaty and subsequent peace, on 2 May 1668 the regiment was disbanded and subsequently reformed on the 14th at the size of just one company, bringing it in line with the other regiments of the army. At this time, the Mademoisselle de La Vallière was replaced by the Marquis de Saint-Gelais, who took over previously on 15 April, and would remain commander until 1669, when the company was expanded back to regimental size. By this time the regiment was known simply as the Dauphin's Cavalry Regiment (Régiment du Dauphin Cavalerie).
Franco-Dutch War
By 1669, the regiment was expanded to the size of 6 companies, and in 1672 the Dauphin ordered the regiment into the newly occupied French Flanders region. However, the new Dutch Republic, which had been formally recognised in 1648 became increasingly interested the Flanders region. Following several reorganisation of the army under the Secretary of State for War François-Michel le Tellier, Marquis de Louvois, the French army was rapidly expanded and formed into new field armies, which could at any time quickly mobilise and strike quickly. As the situation deteriorated, war was declared and the Franco-Dutch War began with the French Royal Army crossing the frontier.