Khomeini's secret dialogue with 'The Great Satan'
2 June 2016 Last updated at 23:14 BST
On 3 June it will be 27 years since the death of Ayatollah Khomeini, the cleric who seized control of Iran in 1979 and re-wrote the history of that country, and the region.
Part of that legacy involves his hard line dealings with the US, or "the Great Satan", as he famously called it.
The BBC has uncovered recently-declassified documents that show Khomeini had a more complex relationship with America than was previously known.
BBC Persian reporter Kambiz Fattahi has gone through those papers, and has this exclusive report.
Filmed by Ian Druce.Edited by Bill McKenna.
Produced by Mat Morrison.