He was born in Anstruther, Fife, the son of Robert Bruce Lockhart, the first headmaster of Spier's School, Beith, Ayrshire, Scotland. His mother was Florence Stuart Macgregor, while his other ancestors include Bruces, Hamiltons, Cummings, Wallaces and Douglases.
At age 21, he went out to Malaya to join two uncles who were rubber planters there. According to his own account, he was sent to open up a new rubber estate near Pantai in Negeri Sembilan, in a district where "there were no other white men". He then "caused a minor sensation by carrying off Amai, the beautiful ward of the Dato' Klana, the local Malay prince… my first romance". However, three years in Malaya, and one with Amai, came to an end when "…doctors pronounced Malaria, but there were many people who said that I had been poisoned". One of his uncles and one of his cousins "bundled my emaciated body into a motor car and… packed me off home via Japan and America". The Dato' Klana in question was the chief of Sungei Ujong, the most important of the Nine States of Negeri Sembilan, whose palace was at Ampangan.[
Lockhart (as he is listed in DNB) developed a talent for their languages and literature. After three years as a rubber planter in Malaya, where his family had interests, he was invalided home in 1910 with acute malaria. The ruggedly handsome, outgoing Scot was first in examinations for the consular service and was sent to Mocow in Jan 1912. Acting consul-general on the eve of the Bolshevik revolution, the fledgling diplomat was quietly recalled for improper involvement with a woman (DNB). But he returned to Moscow in Jan 1918 as head of a special British mission to establish unofficial relations with the new Soviet leadership. The envoy had a letter of introduction to Trotsky from Litvinov but was arrested in Sep 1918 on charges of being a secret agent and imprisoned in the Kremlin. A month later he was exchanged for Litvinov. Ill health kept Lockhart in England until Nov 1919, when he became commercial secretary in Prague. He grew to love Czechoslovakia and developed a lasting friendship with Eduard Benes and Jan Masaryk. In 1922 the diplomat left government service for international banking. In 1928 he joined the London Evening Standard to begin a successful career as a journalist and author. The first of his many highly acclaimed books was Memoirs of a British Agent (1932).
Lockhart returned to the foreign service in Sep 1939, when Britain declared war. In 1940 he became British representative to the Czech government in exile. The next year he was undersecretary of state in the foreign office, heading the political warfare executive. In 1951 he published Jan Masaryck's memoirs. Lockhart died 27 Feb 1970 at Hove, East Sussex.
He had a son from his first marriage to Jean Bruce Haslewood, whom R. H. Bruce Lockhart married in 1913.
His son was author Robin Bruce Lockhart, who wrote the 1967 book Ace of Spies – about his father's friend and fellow agent Sidney Reilly – from which the 1983 miniseries Reilly, Ace of Spies was produced.
Lockhart married Frances Mary Beck in 1948. His posthumous diaries reveal that he struggled most of his life with alcoholism.
