Colin Firth, Rachel Weisz, Ian McKellen and Susan Sarandon have signed to star in The Colossus, a Boer War political thriller, according to Variety.

The film is based on the novel Manly Pursuits by Ann Harries and is being directed by Sean Mathias (Bent), who wrote the screenplay with Myer Taub.

The Colossus tells of ailing arch-colonist Cecil Rhodes' belief that he can only recover his health if he can hear the sound of English song birds outside his window in Cape Town. Ornithologist Francis Wills is hired to transport 500 songbirds to Rhodes's home in South Africa where he falls in love with Olive Schreiner, a local firebrand activist fighting against Rhodes and trying to prevent the inevitable war against the Boers. Wills finds himself at the dangerous center of a daring plot to stop the war.

The movie has a $15 million-budget and shooting is expected to begin in fall 2006.