The BBC Radio 4 historical series that uses documentary evidence to shed new light on the past.

In this Sony Award-winning investigative history series, BBC international correspondent Mike Thomson and guest presenters pore over private papers, public records and primary sources, uncovering the hidden truth about historical events.

As they follow the documentary trail, they talk to key participants, contemporary commentators and academic experts, and explore shocking stories of cover-ups, covert operations and collusion. Here are the extraordinary tales of the 1956 French offer to merge the UK and France, the Wall Street plot to overthrow Franklin D Roosevelt and the journalist's notebook that came perilously close to revealing one of Britain's greatest Cold War secrets.

Plus, Gordon Corera travels to Stockholm to investigate the assassination of Swedish prime minister Olof Palme, David Loyn investigates how a lost document is helping Afghanistan come to terms with its painful past, Heather Jones asks why an intelligence warning given seven weeks before Germany's 1939 invasion of Poland was ignored, and Sanchia Berg traces the career of an MI5 agent left out in the cold....

From the clandestine Nazi radio station in Scotland to an MI6 chief's secret slush fund, the diaries of a Chinese ambassador to the Soviet Union and the CIA's attempts to subvert Albania, Documents that Changed the World will challenge your assumptions and make you question everything you thought you knew about history.

Presented by Mike Thomson, Jeremy Duns, Nick Rankin, Sarah Richardson, Gordon Corera, David Loyn, Heather Jones, Sanchia Berg, Dominic Streatfeild, Anne McElvoy, Dr Yee Wah Foo, Robert Bickers, Arne Westad, Jonny Foo, Andy Cheung, Jo Fox.

Produced by Tom Alban, Kate Borde, Mark Burman, Marya Burgess, James Cook, Isobel Eaton, Neil George, Patrick Gregory, Laurence Grissell, Roger Hermiston, Julia Johnson, Robert Ketteridge, Hannah Loy, Neil McCarthy, Paula McGinley, John Murphy, Sarah Shebbeare, Phil Tinline. Executive producer: Philip Sellars.

First broadcast on BBC Radio 4, 5th September 2005 - 4th December 2017.