In September 1912, half a million men and women signed the Ulster Covenant and vowed to resist Home Rule for Ireland 'by any means necessary'. Some, it was said, even signed in their own blood. To mark its centenary, William Crawley explores the story behind this extraordinary event. One that is cloaked in mystery, myth and misconception but that was to shape the political landscape we live in today.

Presenter - William Crawley, Thanks to - The Somme Heritage Centre, Carol Walker, The Linen Hall Library, Belfast City Council, National Museums Northern Ireland, Dr Vivienne Pollock, Ian Montgomery, Dr William Roulston, Philip Orr, Malcolm Crawford, Keith Haines, Time Johnston, Estate of Frank McKelvey, Parliamentary Archives, Exec Prod for BBC NI - Deirdre Devlin, Exec Prod - Michael Hewitt / Diarmuid Lavery, Prod - Clare McParland, Dir - Brian Henry Martin.

• DoubleBand Films