Lord of the Rings TV series casts young Galadriel

Clarke, who plays Sister Clara in His Dark Materials, joins Will Poulter, Australian star Markella Kavenagh and Years and Years actor Maxim Baldry.

Galadriel is the first recasting of a role from the films; Cate Blanchett originally played the royal elf in the Lord of the Rings and Hobbit trilogies.

The Amazon TV series will be set during Middle Earth's Second Age, thousands of years before the events of the film series, meaning Galadriel is one of the few movie characters who could make an appearance as elves can live for millenniums.

Poulter and Kavenagh will be playing the show's leads Baldor and Tyra respectively, with Game of Thrones actor Joseph Mawle taking on the villain.

Jungle Cruise writers JD Payne and Patrick McKay will be helming the series, with long-term Game of Thrones writer Bryan Cogman serving as consulting producer. Jurassic World: Fallen Kingdom's J.A. Bayona will direct the first two episodes of the series, and stay on board afterwards as executive producer.

So confident are Amazon in the series' success, they have already ordered five seasons, at a reported cost of $1billion.

Clarke is also set to feature in the BBC's upcoming Dracula adaptation, aired on New Year's Day, in which she plays schoolmistress Mina Harker.