Sir Robert Hamilton Bruce Lockhart, KCMG (2 September 1887 – 27 February 1970) was a British diplomat, journalist, author, and secret agent.

Later research suggests that the "Lockhart Plot" was a sting operation orchestrated by Felix Dzerzhinsky with the goal of discrediting the British and French governments.

[3][4] He was born in Anstruther, Fife, the son of Robert Bruce Lockhart, the first headmaster of Spier's School, Beith, Ayrshire, Scotland.

[5] His family were mostly schoolmasters, but his younger brother, Sir Robert McGregor MacDonald Lockhart, became an Indian Army general.

He then "caused a minor sensation by carrying off Amai, the beautiful ward of the Dato' Klana, the local Malay prince... my first romance".

Lockhart also worked for the Secret Intelligence Service, having been given £648 worth of diamonds to fund the creation of an agent network in Russia.

[citation needed] Moura Budberg, the wife of a high-ranking Czarist diplomat, Count Johann von Benckendorff, became his mistress.

[1] In 1918, Lockhart and British agent Sidney Reilly were alleged to have plotted to assassinate Bolshevik leader Vladimir Lenin.

[14] He was accused of leading the "Lockhart Plot" against the Bolshevik regime and, for a time during 1918, was confined in the Kremlin as a prisoner and feared being condemned to death.

However, he escaped trial via an exchange for his counterpart, Maksim Maksimovich Litvinov, the Bolshevik government's representative in London, who had been arrested for engaging in propaganda activities.

[15] Some 20 defendants faced charges in the trial, most of whom had worked for the Americans or the British in Moscow, in the case levied by procurator Nikolai Krylenko.

In late 1922, with the personal debts he ran up exceeding his official salary and feeling the need for change, he resigned from the Foreign Service to accept a position in Prague with the Anglo-Czechoslovakian Bank, on whose creation he had worked.

[citation needed] In 1913, Lockhart married firstly Jean Adelaide Haslewood Turner of Brisbane, Australia, and they had a son, the author Robin Bruce Lockhart, who wrote the book Ace of Spies (1967) – about his father's friend, the agent Sidney Reilly – from which the television serial Reilly, Ace of Spies (1983) was later produced.