The nefarious Faith Militant (a.k.a. The Sparrows) in HBO’s Game of Thrones has a rather well-known inspiration. In the show, the powerful King’s Landing cult that’s playing an increasingly pivotal role during season 5 has a legion of devout followers, violently punishes any perceived sin and is led by a mysterious and manipulative man called the High Sparrow. Author George R.R. Martin frequently uses events and ideas from European history for this A Song of Ice and Fire saga, and the Faith Militant is no exception.
“The Sparrows are my version of the medieval Catholic Church, with its own fantasy twist,” Martin told EW. “If you look at the history of the church in the Middle Ages, you had periods where you had very worldly and corrupt popes and bishops. People who were not spiritual, but were politicians. They were playing their own version of the game of thrones, and they were in bed with the kings and the lords. But you also had periods of religious revival or reform—the greatest of them being the Protestant Reformation, which led to the splitting of the church—where there were two or three rival popes each denouncing the other as legitimate. That’s what you’re seeing here in Westeros. The two previous High Septons we’ve seen, the first was very corrupt in his own way, and he was torn apart by the mob during the food riots [in season 2]. The one Tyrion appoints in his stead is less corrupt but is ineffectual and doesn’t make any waves. Cersei distrusts him because Tyrion appointed him. So now she has to deal with a militant and aggressive Protestant Reformation, if you will, that’s determined to resurrect a faith that was destroyed centuries ago by the Targaryens.”
And there are other, more direct influences as well between Catholic Church and the Faith of the Seven as well, Martin pointed out. “Instead of the Trinity of the Catholic Church, you have the Seven, where there is one god with seven aspects. In Catholicism, you have three aspects—the Father, the Son and the Holy Ghost. I remember as a kid, I was always confused by that. ‘So there are three gods?’ No, one god, but with three aspects. I was still confused: ‘So he’s his own father and own son?’”