I somehow managed to miss this large 4 battalion regiment that was prominent in the Rossbach debacle; it was at the head of the right hand French column and was given a very rough time by Prussian artillery and musketry, as the Susane text below shows with its long list of officer casualties and mention of the loss of 700 other ranks.
Mailly was first raised in 1589 but only admitted into the French army in 1610. 4 battalions strong, so a brigade in itself. The flags are simple as befits one of the older French regiments. Ranked 11th in the Seven Years War.
And this is my translation of the text from Susane Volume 4:
In 1756, when the war at sea began again with the British, the regiment was part of the forces camped near Le Havre and at the end of the campaigning season was based in the towns of Beauvais, Noyon, Soissons and Senlis. It was at Cambrai in 1757, when it received the order to join the army being assembled by the Marshal d'Estrées on the Lower Rhine. Soon after it was at the battle of Hastenbeck where it suffered the loss of 150 men. Captains Durenaud, de Montbel, de Vandires, La Molère, Du Bosse and three lieutenants were wounded there. In the month of October, it joined the army of Saxony, commanded by the Prince de Soubise, and arrived just in time to take part in the disaster of Rossbach. It occupied on this fatal day the right of the second line of infantry behind Piémont, and suffered the same fate as this old corps. The regiment lost 40 officers and 700 soldiers killed, wounded or prisoners, although the regiment had left more than two-thirds of its number in places and in the hospitals of Hanover and Lower Saxony. Lieutenant-Colonel de Boisrenard was wounded and taken, Major La Porterie killed; Captains Monyefroy, Vauvert and Villiers were killed, as were lieutenants Villiers de Beuvran, Laporte, Rique, Dusentre and Girondin. Among the wounded, who almost all were taken prisoner, were Captains Tréville, Saint-Léger, Saint-Féréol, Maillet, Montbel, Boisrenaud, La Mothe, Milly, Durenaud, Preville, Galembert, La Meillerie, Saint-Denis, Bouvet, du Noiret, du Pouerçon, Perrault, Maréchal, Romme, Boudon, Baudemont, du Bosse, Vandières et Dupuis, and 13 lieutenants.
The battalion commander of La Garrigue, who had been detached with 200 men, 15 days before, to guard the lines of communication and the army's magazines, rendered a great service in gathering together the runaways and in covering the retreat. He also saved 120 wagons and rallied 6000 men with whom he was able to evacuate the magazines and the hospitals.
After the disaster of Rossbach the regiment was sent to Hanover which it left in January 1758 to go to Hildesheim, then to Paderborn. It was at Wesel in March and a short time later returned to France. It was employed until 1761 in the defence of the coast of Brittany and had its headquarters in Brest. The regiment was then called Talaru.
In 1759 it repelled an attempted landing by the British in the Bay of Cancalle, and suffered a very strong cannonade from Admiral Harvey's fleet, which wished to capture 14 frigates taking refuge in the port of Conquet. A little while later, a detachment of 200 men, embarked on the fleet of Marshal de Conflans, found itself in naval combat in Belle-Isle. There it lost several officers, among others captains de Boisselet and de Beuvran.
In 1761 the regiment left Saint-Omer, where it had spent the bad season, to rejoin the army on the Lower Rhine. It camped at first below Wesel, took part, on the 21st June in the attack on Luynen, and found itself in the combats of the 15th and 16th July, near to Vellingshausen. It shortly after left the army of the Prince de Soubise and joined that of Marschal de Broglie. On arriving at the camp of Grebenstein, it was ordered, in September, to occupy the forest of Sabbaborg to cover the right of the army. There it was attacked frontally by 1600 of the enemy, while a column of 15,000 of the allies tried to go round to the rear. In this critical position the regiment executed a march of 4 leagues without being caught, and gave, by this splendid manoeuvre, the time for the Comte de Stainville to retreat to the entrenched camp of Cassel.
Mailly, under the name of Chatellux, was in the campaign of 1762 with the same army without taking part in any important operation, and returned to France in March 1763. An ordonnance of 10th December 1762 had changed its name from that of its colonel and given it the title of the province of Guyenne, which until then had been held by a regiment created under Louis XIV, and reformed that year.
And this was the uniform in 1756:
