Archive reveals life of the 'Red Dean of Canterbury'

MI5 kept files on him, his superiors wanted him sacked, and the Army labelled him a defeatist during the Second World War – yet this wasn't the life of a communist spy or dangerous revolutionary, but that of a genteel man of the cloth.

For the first time, the life of one of Britain's most controversial clerics is to be laid bare as historians and archivists delve into the life of Hewlett Johnson: better known as "The Red Dean of Canterbury".

A pacifist, socialist and campaigner for the poor, the Very Rev Johnson, an avowed Christian Marxist, spent more than 30 years as Dean of Canterbury, from 1929 until 1963.

From a humble start, helping people in Manchester slums, he went on to rub shoulders with or enjoy friendship with communist leaders ranging from Chairman Mao, Fidel Castro and Stalin's successor, Georgy Malenkov – incurring the wrath of many of Britain's faithful.

Johnson's family recently gave permission for archivists at Kent University to access the dean's letters (more than 12,000), photographs, diaries, sermon notes and manuscripts deposited there after his death in 1966. Academics expect this massive trove of new material will shed considerable new light on the controversial figure and his dealings with leading communist figures around the world, which led to him being labelled a spy.

Photographs documenting the deanery's more unusual guests – such as Gandhi, considered an unwelcome revolutionary in 1931 – have been discovered. Malenkov, was invited shortly before the Soviets controversially invaded Hungary in 1956. The Very Rev Johnson also made trips to China to visit Chairman Mao and to Cuba, where he met Fidel Castro in 1964.

While Moscow recognised his efforts with the Stalin International Peace Prize, his parishioners were less charitable. One wrote: "Traitor. Resign. You defile the very stones of Canterbury ... England is too good for a Bolshevik."

His outspoken views brought him to the attention of MI5, who monitored his speeches and letters, and even stopped him from lecturing to British troops during the Second World War.

Professor John Butler, a retired health lecturer and author, who is preparing a book on the Red Dean and who is helping the project, insisted Johnson was not a communist spy. "A lot of the material he used about the Soviet Union was supplied directly by Moscow. It is nothing to do with spying. It is absolutely vital to say this – he was not a spy. It was about finding effective people in the West who could be mouthpieces of Soviet propaganda."

Professor Butler added: "He found a way of accommodating what was happening in Russia. That was one of the points where he was perhaps a little naive, politically. He took too much at face value and perhaps did not question it as closely as he might have done."