Yes, a historical book.

Nathaniel Martello-White stars as a cunning and conniving Merlin, whose legendary cave is said to be at the foot of the Tintagel cliffs in Cornwall. A politician to his core, fearless and resolute, Cornwell's Merlin follows his connection to his gods above all else. A far cry from Disney's bumbling depiction in 1963, The Warlord Chronicles' Merlin is obsessed with the lost Treasures of Britain in a bid to restore Britain to its pagan ways, releasing the hold Christianity has taken over the country.

Also, increasingly just mad.

The actor is also way too young. Even at the start of the story (when the narrator is young), Merlin is elderly and even his wife is "now old and toothless".