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!"