Campbell, the son of a respectable Glasgow merchant, and a reputable advocate, assumed the additional name of Colquhoun in 1804 when he succeeded to his mother’s family estate in Dunbartonshire. The Duke of Montrose, commending him to Pitt, 21 Nov. 1804, described him as a friend of the chief baron’s whose claims to be lord advocate were superior to those of Sir James Montgomery, as he was
without dispute a man of higher legal character, of superior eloquence, of known spirit, and acknowledged by all ... acquainted with Scotland, and particularly by the bar ... more capable of the duties of advocate, as a lawyer or debater ... Mr Colquhoun has been most distinguished for his zeal, and forwardness, in resisting Jacobinical principles of all kinds, and was one of the first to propose taking up arms, in that corps (the first regiment of Edinburgh volunteers) which was the first corps of volunteer infantry, composed of gentlemen; and which measure was attended with great effect at the time, particularly in Scotland. Mr Colquhoun was also always distinguished for his attachment to Mr Pitt’s administration, and could not I will venture to affirm ... have been passed over, except for some extraordinary reason.
The duke then protested that his friends in Scotland were being proscribed, and asked to resign office.
Campbell Colquhoun was made lord advocate, with Lord Melville’s approbation, in Portland’s administration in 1807. He was commended, apart from his professional abilities, for his ‘unequivocal support of the protestant establishment in church and state’.
While ‘in purely Scottish business his position gained him a hearing’, the lord advocate was thought not very successful as a speaker on other occasions: when in March 1809 he rose to acquit the Duke of York of blame for the charges against him, he was hooted down by clamour for the question; yet Perceval thought well of his effort.
On 24 Nov. 1810 he informed Perceval from Edinburgh that he would not attend Parliament unless it was urgent: he had, at ministers’ behest, attended ‘much more than my predecessors had been accustomed or required to do’, and to the detriment of professional emolument, domestic comfort and ‘to a certain extent of health’.
In 1816 he succeeded Lord Frederick Campbell as lord clerk register, an appointment that was very unpopular with the friends of Henry Erskine and also with the Duke of Buccleuch, who wanted the place for Lord Home, or at least some other Scottish peerage family. The duke complained to Melville that ‘in order to make law arrangements five years since, it was necessary to carry this pledge to the political pawnbroker to be afterwards redeemed ... Lord Liverpool has got the advocate as a political supporter and has lost me’. Besides, he asked,
has the advocate shown much zeal in support of government? Do we not know how ill he has pulled with many of the friends of government? Is he not notoriously unpopular? As to myself I did once commit the blunder of asking him for a petty situation for a respectable friend which he refused.
A. Fergusson, Life of Erskine, 531-2; Add. 38263, f. 6; SRO GD51/5/507/1, 2.
On 10 Feb. 1818 Colquhoun opposed Lord Archibald Hamilton’s motion against the persecution of state prisoners in Scotland, denying the charges brought forward. In the ensuing Parliament his leaves of absence became even more frequent than before. He was opposed to any kind of parliamentary reform as ‘endangering the whole fabric’.
