Foreign service was not long in coming. On 10th June the regiment, under command of its Lt.Col. the Earl of Pembroke, embarked at Gravesend, disembarking at Bremen on the 21st. From there they marched to join the Army under the command of Prince Ferdinand of Brunswick. Command of the regiment at this time passed to Major William Erskine, as the Earl of Pembroke took up the duties of Adjutant- General.
On the 15th July the Fifteenth arrived at Freysa, and the next day advanced to Speckwinkel, where they were halted with Luckner's Hussars and a battalion of Hanoverians. Meanwhile the Prince of Brunswick led a force to turn the left flank of the French encamped in the mountains near Emsdorf. When shots to the right indicated that this was taking effect the Fifteenth, wearing oak leaves in their hats to show their resolve, mounted and drew swords.
The French had been surprised at a meal, and the attack by the Fifteenth, Luckner's Hussars, and the Hanoverians on the enemies right flank drove them back on Sangstein, the French leaving tents, baggage, and artillery behind. The Fifteenth and Luckner's Hussars cut off the French from the Amoneburg road, and the retreating force threw themselves into a wood beyond the Ohm river. At this the Prince placed himself at the head of the Fifteenth, and accompanied by a few Hussars, they overtook the French on a plain towards Neider-Klein. The Fifteenth charged and broke four bodies of the enemy in rapid succession. Many British Dragoons fell in the battle, but their resolution triumphed. Five hundred of the French separated from the main body surrendered, and the Prince led the Fifteenth and some Chasseurs in pursuit of the remainder, running them to ground in a wood near Neider-Klein, where the French surrendered Prisoners of War, including Major General de Glaubitz and Brigadier General the Prince of Anhalt, 177 other officers, 2482 men, nine pairs of colours (almost all taken by the valiant Fifteenth), five guns, a howitzer, and all the enemy's arms and baggage.
On the 20th, the Prince of Brunswick issued a general order which referred to the action of the 16th July saying "...His Serene Highness, therefore, gives his best thanks to these brave troops, and particularly to Eliott's regiment. His Serene Highness the Prince could not enough commend to the Duke, the bravery, good conduct, and good countenance, with which this regiment fought...."
Battle of Emsdorf by David Rowlands
In this engagement the losses to the regiment were Captain-Lieutenant Basil, Cornet Burt, two sergeants seventy one rank and file, and one hundred and sixteen horses killed, Cornet Parkyns and Cornet Fulford, one sergeant, forty seven rank and file, and fifty two horses wounded.
As a result of this action the Fifteenth were awarded the right to bear on its Guidons and appointments the word 'Emsdorf' - the first battle honour ever awarded to a British regiment.
The regiment continued in North Germany and Holland until January 1763, seeing action at Hoxter (18/08), Dringenburg(25/08), Immenhausen(18/09), Capelnhagen(4/11), Foorwohle(8/11), in 1761. In March 1762 major Erskine was promoted Lt.Col. in place of the Earl of Pembroke (now Maj.Gen..), and he again led the Fifteenth to the field in May 1792, during which year action was seen at Groebenstein(24/06), Homburg (1/07), Friedburg (30/08 - during which action the Fifteenth rescued the Prince of Brunswick from capture by a regiment of French Hussars), and Wetter (September).
Having returned to England in early 1763, the regiment was reviewed in Hyde Park by King George III, on which occasion he was presented with the sixteen stands of colours captured by the regiment in Germany.