LONDON — Michael Fassbender and screenwriter Ronan Bennett are developing a feature film about the legendary Celtic warrior Cuchulain, with Fassbender set to play the leading role.

Cuchulain is the central character in the Ulster Cycle, an epic series of Old Irish legends that date from around the 8th century.

Set in the northern part of Ireland, the saga relates the story of the Ulaid tribe headed by King Conchobar, and particularly its conflict with the rival Connachta tribe led by Queen Mebh.

The most prominent figure in the legends is Conchobar’s nephew Cuchulain, who has semi-divine ancestry and superhuman fighting skills. In the most famous story, known as the Cattle Raid of Cooley, he is the only man capable of resisting the vast army sent by Medb to steal Conchobar’s prize white bull.

Both Fassbender and Bennett, whose writing credits include “Public Enemies” and the recent Channel 4 TV series “Top Boy,” come from Northern Ireland.

They have raised development finance for the Cuchulain project through their London-based production company Finn McCool Films.