In 1987 Burkina Faso's president Thomas Sankara, a revolutionary leader, hero of the pan-Africa movement and fierce opponent of imperialism, was gunned down in a coup d'État. Now, 34 years later, the trial of his alleged assassins is shortly to begin in the capital Ouagadougou. As Rémi Carayol reports, the circumstances of the murder are well known. But what we still do not know is who gave the orders for Sankara's assassination, which brought his Burkina Faso revolution to a bloody end. Nor do we know the role, if any, of foreign powers - including the former colonial power France - in his demise.