of London, merchant, outlived St. John, and took for her third husband Sir Humphrey Sydenham of Cholworthy, Somerset (Foss, vi. 489; Le Neve, Knights, p. 292; Hist. MSS. Comm. 7th Rep. p. 454).
[An account of St. John is given by Wood, Fasti Oxonienses, ed. Bliss. Noble, in his Protectoral House of Cromwell, ed. 1787, ii. 15, gives a life of St. John, quoting a manuscript vindication given by his son, and adding much information about his descendants. Lives are also contained in Lord Campbell's Lives of the Chief Justices of England, 1849, i. 447–78, and Foss's Judges of England, 1857, vi. 475–92.]
ST. JOHN, Sir OLIVER BEAUCHAMP COVENTRY (1837–1891), officiating agent to the governor-general of India in Baluchistan, eldest son of Captain Oliver St. John, Madras army, and of his wife Helen, daughter of John Young, esq., and widow of Henry Anson Nutt, was born at Springfield House, Ryde, Isle of Wight, on 21 March 1837. He was great-grandson of the tenth baron St. John of Bletsho [see under St. John, Oliver, Earl of Bolingbroke]. He was educated at Norwich grammar school, and at the East India Company's military college at Addiscombe, where he took many prizes, and received a commission as second lieutenant in the Bengal engineers on 12 Dec. 1856. He went to Chatham for the usual course of professional instruction, was promoted to be first lieutenant on 27 Aug. 1858, and in the following year went to India, where he was employed in the public works department in the North-West Provinces and Oudh for the next four years.
In October 1863 he joined the expedition to Persia, under Lieutenant-colonel Patrick Stewart, royal engineers, to establish telegraphic communication from India through Persia and Asia Minor to the Bosphorus. His duties lay in the Persian section. He landed at Bushahr in January 1864, and took charge of the fifth and last telegraph division, the most difficult and important of all. From December 1865 to June 1866 he had charge of the directors' office during Stewart's absence, and from June 1866 to January 1867 his own immediate superintendence embraced the line from Tehran to Bushahr.
In May 1867 St. John returned to England, and joined the expedition to Abyssinia under Sir Robert Cornelis (afterwards Lord) Napier [q. v.], as director of the field telegraph and army signalling department of the Abyssinian field force. He laid the telegraph line, under great difficulties, for some two hundred miles from the coast; was mentioned in despatches (London Gazette, 30 June 1868), received the thanks of the government of India and the war medal, and was recommended for a brevet majority on attaining the rank of captain. On his return home in 1868 he was employed to report on the military telegraphs of France, Prussia, and Russia. St. John was promoted to be captain on 10 Nov. 1869, and returned to Persia in 1870, with the local rank of major. Sir Frederick Goldsmid, on being appointed in 1872 arbitrator in the Perso-Afghan boundary dispute, applied for St. John's services, but he could not be spared from his telegraph duties in Persia.
In October 1871 he went to Baluchistan as boundary commissioner of the Perso-Kalat frontier. Having completed the survey of the boundary he returned to England, and during his furlough was employed on special duty at the India office in 1873 and 1874 in compiling maps of Persia and Persian Baluchistan. These maps were based on longitudes of the principal Persian telegraph stations, fixed in co-operation with General J. T. Walker of the Indian trigonometrical survey, Captain William Henry Pierson [q. v.], royal engineers, and Lieutenant Stiffe of the Indian navy, by whom time-signals were exchanged between Greenwich and Karachi on the one hand, and stations in Persia on the other. A result of the Perso-Kalat survey was St. John's ‘Narrative of a Journey through Baluchistan and Southern Persia,’ published in vol. i. of ‘Eastern Persia’ (1876).
In January 1875 St. John was appointed principal of the Mayo College, Ajmir. He was promoted to be regimental major on 29 Aug. 1876. In August 1878 he was attached to Sir Neville Chamberlain's mission to Kabul, which came to nothing in consequence of the amir's refusal to admit it to the Khaibar. In November he was attached as chief political officer to the staff of Sir Donald Stewart, who commanded the Kandahar field force, which entered Afghanistan by the Bolan pass and occupied Kandahar. On 10 Jan. 1879 an attempt was made to assassinate St. John in the streets of Kandahar, but the shot missed him, and the assassin was apprehended. On 29 July he was made a companion of the order of the Star of India. On 26 Dec. some mounted Ghazis ran amuck through the camp at Kandahar, when Major Tytler was wounded, and St. John had another narrow escape. During the occupation of Kandahar he found time to contribute a valuable paper on Persia to the ‘Journal of the Royal United Service Institution of India,’ for which he was awarded the gold medal of the institution for 1879.