After the short peace of Amiens, war was declared again; and when the army was increased, the Gordon Highlanders were strengthened by the addition of a second battalion, and Major Cameron marched with it to Weely in England, to join the force mustered to oppose the expected invasion by Napoleon. The invasion ended in smoke; but the battalion remained cantoned in England until 1807, and in the preceding year lined the streets of London during the funeral of Nelson. Fassifern embarked with them at Harwich on the Danish expedition, under Lord Cathcart; and, for the first time, served under Wellington—then Sir Arthur Wellesley—at the attack on Kioge, where Lieutenant-Colonel Napier, at the head of the Highlanders, charged the Danes, who were routed with the loss of their artillery.
After the bombardment of Copenhagen, and the return of the troops to Britain, Major Cameron, in consideration, of his services, received a brevet lieutenant-colonelcy on the 25th April, 1808; a full lieutenant-colonelcy on the 23rd June following; and was shortly afterwards ordered on the Swedish expedition under Sir John Moore, who led 10,000 men to assist Gustavus Adolphus IV., a gallant but fiery and intractable prince, against whom Russia and France had united their arms. The violent temper of the Swedish monarch rendered this undertaking completely futile, and, without achieving anything, the expedition returned to Britain.
As junior lieutenant-colonel, Cameron now remained with the second battalion at home; while the first, under Lieutenant-Colonel Napier, accompanied Sir John Moore a third time on that fatal service, from which he never returned. In 1809, the gallant Napier fell with his leader at Corunna, and then Fassifern obtained the command of the first battalion, committing the second, in February, to the care of Lieutenant-Colonel Lamond, of Lamond. Thus, at the early age of thirty-seven, and after only fifteen years' service, he found himself at the head of one of the finest Scottish regiments in the service of his country.
In July, with the right wing of the first battalion, he embarked on board H.M.S. Superb, 74, at Harwich, on the great expedition under the Earl of Chatham, in Sir William Erskine's brigade. He was at the landing on Breesand in Walcheren, and the occupation of Ter Goes on South Beveland. He landed with 998 Highlanders; but so fatal was the Dutch pestilence, that in October only 250 of them were on parade; and the grenadier company, which was entirely recruited from Aberdeenshire, was reduced to two sergeants and three privates. Cameron deeply regretted the loss of his men. The first who died was a fine young clansman, whom he had brought with him from Lochaber, and he attended his funeral in the churchyard of a neighbouring village. After addressing the soldiers on the merits of the deceased, "Cover him up with the greenest sods," said he, "for he was a brave lad, a good soldier, and true Highlander!"
On its return from this disastrous service, his battalion occupied Woodbridge Barracks in England. At this time an Englishman obtained an ensigncy in the corps, which Cameron considered an innovation; for while, on one hand, he disliked the French, from old associations, on the other, he was not, for the same reason, over partial to Englishmen, and was wont to affirm, "that a Southern in the kilt reminded him of a hog in armour." Unfortunately for himself, Ensign Mudge (for such was the name of the new acquisition) had no particular love for the kilt, at which he railed on all occasions, in very coarse terms, and once particularly at an Artillery hall in Woolwich, which so roused Cameron's Highland ire, that he vowed, "if such remarks were ever made again by Ensign Mudge, he would bring him to a general court-martial!" At this time, the officers of the 42nd wore the kilt constantly by their own desire.
Undeterred by Cameron's threat, Mudge wrote to the Commander-in-Chief, stating that his health would not permit him to wear a dress so unchristian and uncivilized. Sir David Dundas addressed an answer, not to him, but to Fassifern, stating that his Majesty had no further use for the services of poor Mr. Mudge, on whom this result, which Cameron and his Highlanders hailed with satisfaction, fell like a thunderclap.
While at Woodbridge, he invited to the mess Dr. Moore (the venerable father of the hero of Corunna), who afterwards addressed to him a letter, expressing his high sense "of the kind and social reception" he had met with from him and his officers. After this, in July, 1810, the battalion marched to Canterbury, previous to embarkation for Spain; Cameron obtained a short leave of absence, and so much had he become attached to the corps, that he wept when he left it even temporarily. On revisiting his native glen, his aged father, then in his seventieth year (the old laird was born in 1740), expressed great reluctance to part with him again, for, like a true Highlander, he had some dark forebodings of the future.
His three sisters were married: Mary, to M'Donald of Glencoe; Jean, to Roderick M'Neill of Barra; and Catherine, to Cluny M'Pherson; his eldest brother Duncan was practising as a writer to the signet, in the capital; and Peter, the second, was away to India in command of the Balcarras. The old laird was almost alone at Fassifern; he represented to the colonel, that, though he was only thirty-nine years of age, he had received two wounds, from one of which he still suffered; that he had been many times engaged with the enemy, and had seen enough of war. He urged him to settle at home and to marry; offering him his second estate of Arthurstone, in Angus; but the love of his profession was too strong in the heroic heart of Cameron, and he rejoined his battalion, then under the command of Major Archibald M'Donell (of the family of Keppoch), at the far-famed Lines of Torres Vedras.
To make his regiment as efficient as possible, he ordered that no officer who had been less than ten years in the service should ride on the march; this diminished the number of useless horses which every regiment then possessed; while to increase the number of bayonets, he turned the whole of the band into the ranks; thus, throughout the whole Peninsular War, he retained only the bagpipes, drums, and fifes. His regiment belonged to the 1st Brigade, or General Howard's, in the 2nd Division of Infantry, or Lord Hill's, with the 50th, under Colonel Stuart, and the 71st Highlanders, under Colonel Cadogan, with both of whom his fiery temper and jealousy on points of etiquette soon involved him in a coolness that lasted till they were both removed by death. The Highlanders entered Spain by the way of Albergaria, and their peculiar garb soon changed the constant cry of "Live the English," to "Viva los Escotos! Viva Don Juan Cameron, y sus valiante Escotos! Viva!"
This was when following up the retreating Massena. Notwithstanding all efforts of that general to restore the barbarities of ancient warfare, much good feeling prevailed between the French and British when out of the field. Of this, one anecdote will suffice.