The 'Secret Peacemaker,' Brendan Duddy has died at the age of 82.
The Derry businessman had been unwell following a stroke some years ago and was taken to hospital earlier this week with what is believed to be pneumonia.
At the height of the conflict in Northern Ireland, Brendan Duddy acted as a go between between the Provisional IRA and the British government.
He was in regular contact with a senior British Intelligence agent, relaying messages between the two sides even as the security situation deteriorated.
Brendan Duddy himself rose from being the owner of a chip shop in Derry to being a major businessman in the city.
In an interview with Peter Taylor he claimed he first met the Sinn Fein leader Martin McGuinness when he was delivering burgers to his chip shop.
In later years the work of the two men would be invaluable in bringing the conflict here to an end.
During the 1981 Hunger Strikes at a time when Anglo Irish relations were at an all time low Brendan maintained his contact and attempted to get the British Government to move before the situation worsened but the British Prime Minister Margaret Thatcher thwarted efforts to bring the prison hunger strike to an end.
Codenamed 'The Mountain Climber' Brendan Duddy renewed his efforts and in 1991 he was able to bring Martin McGuinness and Michael Oatley together face to face in a meeting that later led to the development of the peace process.
Jonathan Powell the former Chief of Staff for Tony Blair claimed that if it had not been for the contact maintained through Brendan Duddy the peace process might not have been possible.
When it became public knowledge that the British government had back channel contact with the IRA there was condemnation from among others DUP leader Ian Paisley.
Powell claimed that later the DUP opened up their own back channel to keep in contact with Sinn Fein.
Brendan Duddy himself refused to talk about a lot of his work and his private archives were donated to the James Hardiman Library in the University of Galway.
This archive opened in 2011.