The partners will serve as producers on The Young Victoria, with Jean-Marc Vallee of C.R.A.Z.Y. fame set to direct from a screenplay by Julian Fellowes.
The story will chronicle the longest serving monarch's early rise to power in the 19th century, focusing on the turbulent early years of her reign and her romance and marriage to Prince Albert.
King was introduced to the project by The Duchess of York Sarah Ferguson, who is also attached to produce. Ferguson provided insights into little-known characteristics of Victoria, who was 18 when she became Queen in 1837 and ruled for 64 years until 1901.
'We all think we know Queen Victoria from the latter part of her life but in fact she was an amazing, dynamic, romantic personality from a very early age that is largely unknown,' King said. 'I had been searching for a British project for many years so am just thrilled to bring her story to life. And to do so in partnership with Marty is a special joy.'
Tim Headington, King's regular finance partner on non-Warner Bros projects, rounds out the producers' suite. Denis O'Sullivan will oversee the project for Initial Entertainment Group.
Vallee's coming-of-age film C.R.A.Z.Y. won 11 Genie Awards and 15 Jutra Awards, the Best Canadian Film prize at the Toronto International Film Festival in 2005, and the Golden Reel Award as Canada's top box office performer.
Fellowes won the 2002 Academy Award for his Gosford Park screenplay and wrote and directed the thriller Separate Lies in 2005.
Initial Entertainment Group has garnered 38 Academy Award nominations since its inception 12 years ago. Credits include Gangs Of New York and The Aviator - both directed by Scorsese - as well as Blood Diamond, Traffic, Ali, and the upcoming epic adventure Shantaram.