In November he was transferred to the divisional command of the Peshawur District, a more important, but also a more unquiet post than Rawul Pindi. Thenceforth for three years he was to be the Warden of the turbulent north-western frontier. It pleased him to find in his command his old regiment the Ninety-Eighth, and also the Sixty-First which he had led at Chillianwallah. When in February, 1850, Sir Charles Napier reached Peshawur on a tour of inspection, Sir Colin was able to assemble for review quite a little army of all ranks; three troops of horse-artillery and two field-batteries, three cavalry regiments, three European and three native infantry regiments. While Sir Charles was in Colin Campbell's district, it happened that he came under hostile fire for the last time in his tumultuous life. Between Peshawur and Kohat, both places in British territory, a mountain road ran outside that territory through a long and dangerous defile. The Afridis inhabiting the intervening hill country had complained that their subsidy for keeping open the pass had not been paid, and in revenge had slaughtered a working party of sappers and miners. Sir Charles determined to force the defile in person. Campbell, on Napier's requisition, detailed a tolerably strong force as escort to the Commander-in-Chief. It chanced that before starting Napier inspected a regiment of irregulars under the control of the much-vaunted Punjaub Government. The men were of fine physique, but "one soldier had a musket without a lock, another a lock without a musket. A stalwart soldier, his broad chest swelling with military pride, his eyes sparkling with a malicious twinkle, held on his shoulder between his finger and thumb a flint—his only arm." The defile was duly forced, but its passage was one long skirmish. Kohat was inspected and reinforced, but Napier, on commencing his return march, found that the pickets left to keep the road open had been roughly handled and had suffered serious loss. The Afridis were very daring, and actually fired on Sir Charles and his staff at short range. The loss sustained in this somewhat quixotic expedition amounted to one hundred and ten men killed and wounded—"not much," comments Napier grimly, "when one considers the terrible defile through which we passed, defended by a warlike race." His biographer calls the enterprise an "interesting episode"; it certainly was not a very wise enterprise to be undertaken by the Commander-in-Chief of British India. It was Napier's last eccentricity of a military character. By the end of the year he resigned the command of the army of India, and was succeeded by Sir William Gomm, an old brother officer of Colin Campbell in the Ninth in the Peninsula days.
In March, 1851, Lord Dalhousie visited Peshawur and discussed with Sir Colin the policy to be adopted towards the troublesome and turbulent tribes on the north-western border. Scarcely had the Governor-General gone when news came in that a Momund tribe, of the region north of Peshawur between the Swat and Cabul rivers, had been raiding into British territory. Dalhousie left to Sir Colin the decision whether to make signal reprisals or to adopt defensive measures, and, as the result of the description of the wild and rugged region sent him by Sir Colin after a reconnaissance he had made, elected for the defensive as an experiment. It failed, for in October the Momunds of Michni made an irruption upon some villages within British territory. The Governor-General now decided on an immediate resort to active measures, and Sir Colin was ordered to inflict summary chastisement on the offending tribe. He marched from Peshawur on October 25th with a force of all arms about twelve hundred strong, and advanced to the confines of the Michni territory. He did not hurry, because he desired that his political officer should have opportunity to inform the inhabitants of the conditions intended to be offered them; which were annexation of the territory, exile for the irreconcilables, and the retention of their lands by the cultivators on payment of revenue. Campbell's humane view was that "to drive into the hills the whole population of Michni, occupying some seven and twenty villages, could only result in forcing them to prey on the plunder of the villages inside the border." The villages and fortalices whose inhabitants were implicated in the violation of British territory were destroyed under a harmless fire maintained by the mountaineers; but, as Campbell records, "while engaged in duties in which no soldier can take pleasure no lives were lost on either side. God knows the rendering homeless of two or three hundred families is a despicable task enough, without adding loss of life to this severe punishment." The British camp was more than once assailed by bodies of Momund tribes, and one of those attacks was made by some five thousand hillmen whom Sir Colin dispersed by shell fire. A fort was built and garrisoned in the Michni country, and the field-force returned to Peshawur in February, 1852. With the results it had accomplished the Governor-General expressed his entire satisfaction.
The column had scarcely settled down in Peshawur when fresh troubles were reported from the wearyful Momund frontier. Sir Colin hurried thither with two horse-artillery guns and two hundred and sixty native troopers, to find the Momund chief Sadut Khan in position on the edge of the Panj Pao upland, fronting towards Muttah, with six thousand matchlock men and some eighty horsemen. The affair had its interesting features. Sir Colin took in reverse the Momund hordes with his artillery fire, broke up their masses, put them to flight, and pursued them. As he was preparing to return the Momunds suddenly wheeled in their tracks and rushed upon him over the broken ground. The guns were instantly unlimbered, and double charges of grape checked the wild and gallant attack,—a brilliant rally after the endurance of two hours' shell fire followed by a hasty retreat. The mountaineers continued to press Campbell's slow retirement across the table-land, notwithstanding the fire of grape which he maintained. The incident strengthened his belief in the superior efficacy of defensive operations, and he declined to fall in with the anxious wish of the Punjaub Board of Administration that he should act on the offensive against the Momunds, on the ground that he was not prepared to execute operations of that character without the most precise orders by the Commander-in-Chief, the authority to which he was responsible. His reply met with the full approval of the Commander-in-Chief, which however the Governor-General did not share. Sir Colin maintained his ground with the approval of the former authority, when pressed by the Commissioner of Peshawur to enter Swat. Meanwhile the Ootman-Kheyl tribe had become implicated in the murder of a native official in British employ at Charsuddah. Sir Colin had no hesitation in taking measures to inflict punishment on this powerful and turbulent clan. A column of all arms, two thousand four hundred and fifty strong, was assembled on the left bank of the Swat river, and on May 11th proceeded to destroy a group of deserted villages belonging to the Ootman-Kheyl. The column then advanced on the large village of Prangurh, the Ootman-Kheyl stronghold. It had been prepared for defence, and was crowded with men who opened fire on Sir Colin's advanced guard. Covered by artillery fire his troops carried the village with a rush, after a stout defence on the part of the enemy. During the destruction of Prangurh letters were found proving a strong feeling of hostility towards the British Government on the part of the rulers of Swat. Sir Colin then fell in with the views of the Commissioner, and declared himself prepared to invade the Swat territory unless he should be absolutely prohibited by the Commander-in-Chief.
The British force next moved upon Iskakote, a large village of Ranizai, a dependency of Swat, whither large bodies of hillmen hastened to defend the village and valley. Sir Colin estimated the number of the hostile clansmen to be not less than six thousand. They made a stubborn resistance, and endured a sharp cannonade with great firmness. The Guides and Ghoorkas stormed the nullah with some hand-to-hand fighting, whereupon, having suffered severe loss, the enemy broke up and made for the hills pursued by the cavalry.
The Commander-in-Chief interposed no veto on the invasion of Swat, but it became apparent to Sir Colin Campbell that the transport for that operation was inadequate and inefficient. Experience of the opposition he had encountered in the Iskakote affair, and a subsequent reconnaissance in the Ranizai valley, convinced him that his infantry would require a reinforcement of two thousand five hundred men, without receiving which he could not proceed to the invasion of Swat. The Punjaub Board of Administration refused his requisition for the number of troops he asked, and as it was unadvisable to keep the force in the field in the hot weather, the column returned to Peshawur in the beginning of June.
Campbell had already been made aware by the Commander-in-Chief of the Governor-General's dissatisfaction, which in the shape of a formal censure awaited him at Peshawur. Lord Dalhousie used expressions which must have cut the old fighting man to the quick. His lordship chose to tell the soldier of many battles that he had manifested "over-cautious reluctance" in advancing against the Swat marauders in March. Presently came the further charge that not only had he "transgressed the bounds of his proper province," but that "he had placed himself in an attitude of direct and proclaimed insubordination to the authority of the Governor-General in Council." Campbell replied with disciplined dignity and self-respect, expressing his regret that expressions so strong should have been used in regard to him, and his painful surprise that after a lifetime of unswerving military subordination he should be accused of the reverse. He was aware that he was in disaccord with the Government, and already when in the field he had determined to resign his command, an intention which he had communicated to the Commander-in-Chief. To that old friend he wrote without heat:—"I have come to the conclusion that I should be wanting in what is due to myself, if, after what has passed, I were to continue in this command; there is a limit at which a man's forbearance ought to stop, and that limit has in my case been reached."
Sir Colin resigned his command on July 25th. He declined a farewell banquet to which the officers of the Peshawur garrison desired to invite him, believing that in the circumstances to accept the honour would be contrary to the spirit of the Queen's regulations. After spending three months in the bracing hill-station of Murree, in the end of October he visited at Dugshai the Ninety-Eighth regiment, to his original position as senior lieutenant-colonel of which he had reverted on the resignation of his divisional command; then, after a brief visit to Simla, he sailed from Bombay, arriving in England in March, 1853. Before leaving India he had read the official acknowledgment by the Government of the services of the troops engaged in the recent operations. The despatch recorded the Governor-General's regret "that any incident should have occurred to deserve a censure of any portion of Sir Colin Campbell's conduct;" but it "acknowledged in the most ample terms the ability, the personal intrepidity and activity, and the sterling soldierly qualities, which this distinguished officer had displayed in the military command of the troops at Peshawur upon every occasion on which they had taken the field." The amende honorable was well enough in its lumbering way; but it could scarcely take away the bitter flavour of the barbed and venomous insinuation conveyed in the cruel words "over-cautious reluctance."