In 1815, following his final defeat at Waterloo, French emperor Napoleon Bonaparte (Kenneth Haigh) arrives at St. Helena, the barren, wind-swept South Atlantic island to which the British and their allies have exiled him. Guarding Napoleon are troops led by English general Sir Hudson Lowe (Ralph Richardson), the island's governor.
Although Lowe allows Napoleon and his small entourage his valet, Haitian bodyguard General Gourgaud (Moses Gunn), and chief aide Count Bertrand (Ferdy Mayne) and Bertrand's wife (Billie Whitelaw) to move freely around the island, Napoleon bristles at the idea of being Lowe's prisoner.