In 1757 the regiment was in the second line at the battle of Gross-Jägersdorf on 30th August and suffered heavy casualties; according to Engelmann, "in the thick Norkitt Forest, amid powder smoke and battle noise, it began to shoot at its own first line by mistake, taking them for the Russians. This confusion made the Russian counterattack possible". It was at Schweidnitz in 1758 and the grenadiers saw action at Zorndorf (over 30% casualties - Duffy), Kay and Kunersdorf (around 30% casualties - Duffy). From 1760 the 1st battalion was with Prince Henry in Silesia and Saxony. The other battalions were firstly at Breslau and Neisse, then Neisse, Trachenburg and Militsch in 1762. The 1st battalion and grenadiers fought in the battle of Torgau in 1760, as well as at Freiberg in 1762. The regiment retained 3 battalions at the peace in 1763 unlike the other garrison regiments that returned to their pre-1756 establishment.
This is the most elaborate style of garrison regiment flag, carried only by regiments 1 and 2. It is very similar to the flags carried by many of the regular line infantry regiments, except for the wreaths which are in the style carried by the other garrison regiments and which are very similar to the design of wreath used on the flags of the regiments of Frederick William I, Frederick's father. The regimental flag design is shown at the top (Kompaniefahnen), the Colonel's flag (or Leibfahne) at the bottom.
And this plate shows the relatively plain uniform of the regiment, typical of those of the garrison regiments:
(I shall shortly add uniform plates for the other two garrison regiments whose flags I have depicted.)