A brief biography was given in Brown's 1881 Directory
On the 29th January, 1863, Henry Brougham Loch, Esq., C.B., was appointed Lieutenant-Governor in succession to the late F. Pigott, Esq. Mr Loch was the youngest son of James Loch, Esq., of Duylaw, formerly M.P. for Kirkwall, and was born in 1827. in 1844 he entered the Hon. East India Company's Bengal Cavalry, and as aide.de-camp to Lord Gough, served through the Sutlej campaign. After holding the adjutancy of his regiment three years, be was appointed second in command of Skinner's Horse in 1851. He returned to England early in 1854, and volunteered his services to the army in Bulgaria to assist in organising the Turkish cavalry. He accompanied the army to the Crimea, and was present at the battle of the Alma. He resigned his commission in the East India Company's service, and afterwards joined the Cheshire Yeomanry. In April, 1857, he accompanied the Earl of Elgin on his mission to China as first attache, and was selected by that nobleman to bring borne the treaty with Japan, signed at Jeddo, in August, 1858. On his return to China he was selected to fill the office of private secretary to Lord Elgin, and he continued to hold that office until he was, in 1860, treacherously captured by the Chinese during the hostilities carried on in that year between the two countries, and, together with Mr Parkes, the English Consul, suffered the most barbarous indignities. An indemnity of £100,000 was, on the conclusion of peace, exacted from the Chinese for the families of the imprisoned and murdered captives; but the prisoners set at liberty generously gave their share of it to the families of those who had been murdered. Mr Loch brought home the Convention of Pekin, and the ratified Treaty of Tient-sin, and for his services was made Companion of the Bath. He also had the honour of being invited to dine with her Majesty, to whom he related the incidents of his captivity; and soon after received the appointment of private secretary to Sir George Grey, Secretary for the Home Department. From this brief and necessarily imperfect sketch of the varied career of Mr Loch, it will be seen that he is a man of great activity and experience, who had seen military and diplomatic service in all parts of the world; and the reader will be prepared by it to anticipate much of that untiring energy and ability which have since marked his administration of Insular affairs. Commenting upon his appointment to the governorship of the Isle of Man, the London Times said:-" The public will hear with pleasure of this small mark of royal favour bestowed upon a gentleman whose sufferings in the prisons of Pekin two years ago excited so much sympathy not only by reason of their severity, but also by the gallant bearing with which they were endured."
Awarded KCB in September 1880 and almost immediately indicated he would be willing to be a Commissioner of Woods and Forrests - a considerably less well paid job but one that would enable him to move to London - he was appointed a Commissioner in 1881 with his resignation as Governor taking place on 22 March 1882; within two years of returning to London he had been appointed Governor of the State of Victoria, Australia.
His wife, Elizabeth Loch, daughter of the Hon. Edward Villiers, and grand-daughter of Earl Villiers was considerably younger than he, being only 19 when she came to the island in 1863, Katherine Forrest gives a brief pen-picture of her. She was a driving force behind the establishment of the Douglas School of Art.
DNB: 'has no mention of IoM career!'
D. Winterbottom Governors of the Isle of Man since 1765 Douglas: Manx National Heritage 1999 (ISBN 09524019-5-9)