Lawrence of Arabia told the cabinet at the end of the first world war that there was no case "for separating Sunni and Shia Arabs", an extraordinary foreshadowing of the issues at stake in this weekend's Iraqi constitutional vote, overseen by US and British occupying forces. TE Lawrence's ideas are shown in a recently unearthed map that is one of many uncanny links between past and present in an new Imperial War Museum exhibition marking the 70th anniversary of his death in 1935.

The artefacts, photographs and documents catalogue the deepening involvement of Britain in the postwar Middle East and the fateful changes that shaped today's still turbulent region. Lawrence felt Arab hopes had been betrayed by the secret wartime carve-up that gave France control of Syria and Lebanon and Britain of Palestine - where the Jews had been promised a "national home" - and Transjordan. Prince Faisal, Hussein's son, became king of Iraq and his dynasty ruled until it was overthrown by the precursors of the Ba'ath party.

Tales of derring-do go alongside the geo-politics. Exhibits include Lawrence's silk robes, Arab headdress and Lee Enfield rifle (notched to mark the killing of a Turkish officer). There is the white flag raised at the surrender of Jerusalem and rusting bits of the Hejaz railway where he honed his guerrilla techniques. The IWM has even tracked down the Brough Superior SS100 motorcycle he was riding when he was killed.

Lawrence's stylish wit is much in evidence. So, too, is the depressive side that led him to despair and anonymity. Controversy about his sexuality - he was raped by a Turkish official and paid to be flogged while serving incognito in the postwar RAF - is not settled. And there is still mystery about the identity of the "SA" to whom he dedicated his master-work, Seven Pillars of Wisdom. A colleague called him: "An odd gnome, half cad, with a touch of genius."