After this victory the Royal Scots marched towards the coast, and were engaged in the siege of the strong fortress of St. Sebastian. A breach having been made on the left flank, Major-General Hay was directed to storm the fortress with his brigade, of which the Royal Scots formed a part.
The battalion had passed the night of the 24th of July in the trenches. At day-break on the following morning it led the attack under the orders of Major Peter Fraser, and, though exposed to a most destructive shower of grape and musketry, which thinned the ranks, it advanced in the teeth of this storm of fire, in the most cool and determined manner. Major Peter Fraser, while gallantly encouraging his brave followers by his example, was killed; and Captain Mullen, being next in seniority, assumed the command of the battalion, which duty he performed with much credit. Though the cannon of the fortress thundered in front, the French soldiers poured down their volleys of musketry, and hand-grenades, shells, and large stones, flew in showers through the darkened air; yet onward went the Royal Scots, and assailed the breach with a degree of valour and intrepidity which rivalled the gallant exploits of their predecessors under the great Gustavus Adolphus. But the defences round the breach had not been destroyed, and success was found to be impossible; the storming party was consequently ordered to retire.[116] The battalion lost, on this occasion, Major Fraser, Captain Cameron, Lieutenants Anderson, Clark, Massey, and Adjutant Cluff, 6 serjeants, and 75 rank and file, killed; Captains Arguimbeau, Logan, Stewart, Macdonald, and Buckley, Lieutenants O'Neil, Eyre, and Reynolds, Volunteer Miller, 7 serjeants, and 230 rank and file, wounded; Lieutenant Reynolds died of his wounds, and Lieutenant Eyre was taken prisoner.
The siege was afterwards prosecuted with vigour, and on the 31st of August the fortress was again attacked by storm. The Royal Scots, commanded by Lieut.-Colonel Barns, were directed to make their attack on the left of the second breach, and were supported by the 38th regiment. The assault was made with great gallantry; some of the traversers of the semi-bastion were carried by the leading companies, but were retaken by the enemy. Nothing could exceed the bravery and steadiness of the troops employed at this point; and the enemy, observing the whole division in motion, sprung a mine on the top of the curtain; but the explosion was premature, and only a few of the leading men of the Royal Scots suffered from it. Yet undismayed by the bursting mine, and fierce opposition of the enemy, the Royal Scots pressed forward upon their adversaries, and carried the coverlain; the troops crowded into the town in every direction, and in the course of an hour were masters of the place, excepting the citadel.[117]
On the 8th of September batteries mounting fifty-four pieces of ordnance opened a tremendous fire upon the citadel. In less than three hours the enemy hoisted a flag of truce, and, after some discussion, surrendered. As a testimony of the royal approbation of the signal valour evinced by the Royal Scots during this siege, and of the value attached to their services, they were permitted to bear the words "St. Sebastian" on their colours. Their loss in the successful storm of the town was, Ensign Boyd, 3 serjeants, 1 drummer, and 48 rank and file, killed; Lieutenants Armstrong, Holebrooke, Macdonnell, Clark, and Suckling, 7 serjeants, and 133 rank and file, wounded. Captain James Stewart, who was performing the duty of aide-de-camp to Major-General Hay, was killed from the castle while reconnoitring the works on the 4th of September. Captain Robert Macdonald was promoted to the rank of Major in the army, for his distinguished services at the storm of St. Sebastian.
After the capture of this fortress the troops advanced to the frontiers; and on the 7th of October the light company of the Royal Scots, commanded by Lieutenant J. N. Ingram, crossed the Bidassoa, followed by the remainder of the battalion and that portion of the army which had reduced St. Sebastian; the Royal Scots being the first British corps of the allied army which entered France. Thus, after driving the legions of Napoleon out of Portugal and Spain, the seat of war was transferred to the enemy's country; and the interior of France became the scene for the display of British prowess. After crossing the Bidassoa the troops drove the enemy to the heights of Irun, a distance of about three miles.
On the 10th of November the enemy's formidable line of works on the river Nivelle were attacked, and the Royal Scots, with the other regiments of the 5th division, drove the enemy from a field redoubt, and pursued them under the guns of Bayonne. The battalion lost, on this occasion, 1 rank and file, killed, and 4 serjeants and 15 rank and file wounded. Further operations were retarded by snow and rain; but in the early part of December the army passed the river Nive, and drove the French into their entrenched camp in front of Bayonne; from whence they issued on the three following days, and attacked the allies, but were repulsed. The Royal Scots were warmly engaged on these occasions, and their gallantry was rewarded with the royal permission to bear the word "Nive" on their colours. Their loss was 3 rank and file killed, and 1 serjeant and 3 rank and file wounded.
4th Batt.
In the meantime important events had transpired on the continent of Europe. The invasion of Russia by Napoleon, the burning of Moscow, the disastrous retreat of the French army from the north, and the separation of Prussia, Austria, and other states, from the interest of Napoleon, were followed by a treaty of alliance and subsidy between Great Britain and Sweden, in which it was stipulated that a Swedish army commanded by the Crown Prince should join the allies; and on the 2nd of August, 1813, the 4th battalion of the Royal Scots embarked under the command of Lieut.-Colonel Muller for Stralsund, in Swedish Pomerania, forming part of an expedition sent thither under the orders of Major-General Gibbs. Thus a battalion of the regiment proceeded to the same part of the world to which a body of daring Scots, who formed the nucleus of this distinguished corps, proceeded exactly 200 years before, to engage in the service of the Swedish monarch. The battalion remained at Stralsund until the middle of December, when it advanced to support the army of the Crown Prince of Sweden on the Elbe, and halted on the 24th of December at Lubeck.
Thus at the conclusion of the year 1813 the regiment had four battalions on foreign service in three different quarters of the globe; namely—
| 1st | battalion in | Upper Canada, | America. |
| 2nd | " | the East Indies, | Asia. |
| 3rd | " | France, | Europe. |
| 4th | " | Germany, | " |