Under Byzantine rule, the island was divided into districts called "mereíai" (μερείαι) in Byzantine Greek, which were governed by a judge residing in Caralis and garrisoned by an army stationed in "Forum Traiani" (today Fordongianus) under the command of a "dux". During this time, Christianity took deeper root on the island, supplanting the Paganism which had survived into the early Middle Ages in the culturally conservative hinterlands. Along with lay Christianity, the followers of monastic figures such as Basil of Caesarea became established in Sardinia. While Christianity penetrated the majority of the population, the region of Barbagia remained largely pagan and, probably, partially non-Latin speaking. They re-established a short-lived independent domain with Sardinian-heathen lay and religious traditions, one of its kings being Hospito. Pope Gregory I wrote a letter to Hospito defining him "Dux Barbaricinorum" and, being Christian, the leader and best of his people. In this unique letter about Hospito, the Pope prompts him to convert his people who "living all like irrational animals, ignore the true God and worship wood and stone" ("Barbaricini omnes, ut insensata animalia vivant, Deum verum nesciant, ligna autem et lapides adorent").