Game of Thrones tells the story of Britain better than most histories

A young pretender raises an army to take the throne. Having recently learnt of his father’s beheading, the adolescent — dashing and charismatic and descended from the old kings of the north — vows to avenge him. Despite his youth, he has already won in the field and commands the loyalty of many of the leading families of the realm; he is supported in this war by his mother, who has spirited away her two younger boys to safety. Pitted against them is the Queen, proud and strong-willed, and more of a man than anyone around her, battling for the inheritance of her sadistic young son.

This is the premise behind the HBO television show Game of Thrones, the fourth series of which begins on 7 April. Based on the George R.R. Martin heptalogy, A Song of Fire and Ice, and set on the island of Westeros, it has broken out of the fantasy genre to become one of the most popular shows of this, our golden age of television.

The great attraction — apart from the sex and violence, of course — is that GoT has a huge number of characters we actually care about, even though many are vile. It is a hard, horrible, medieval world, and the most sympathetic characters are so precisely because of misfortune; most of all the dwarf Tyrion Lannister, played by Peter Dinklage as a charming, sex-mad rogue with a melancholy air whose father never forgave him for causing his mother’s death in childbirth. There is also Jon Snow, Ned Stark’s bastard who has gone to fight for the Watch, a sort of Templars who protect ‘the Realm’ from the Wildings (who are basically Scots Highlanders).

Obviously, this being fantasy, the devotion of its fans reaches an almost alarming level; there are at least two extensive wiki sites on which the entire world Martin created is chronicled, with pages on obscure kings, gods, ancient battles, and, yes, you might well think that none of this actually happened.