From its very beginnings, “Game of Thrones” has been riddled with sexual brutality. The franchise, which started as a series of fantasy novels by George R. R. Martin about a bleak, feudal world, has at various times included a warrior king who claims his child bride on their wedding night, and the gang rape of a young woman by “half a hundred shouting men behind a tanner’s shop.”

These scenes and others have raised concerns, but this discussion was confined to readers and critics of fantasy fiction.

Now the debate about the series’s sexual violence has spilled into the mainstream and grown vehement, fueled by the explosive growth of HBO’s “Game of Thrones” series. In its fourth season, the show, which airs on Sunday nights, averages more than 14 million viewers and has become its cable network’s most watched series since “The Sopranos.”

In the latest episode, women held captive in a wintry shelter are sexually brutalized. In the deeply controversial episode that preceded it, a scheming noblewoman in an incestuous relationship with her brother is forced to have sex with him, despite her cries of no.