San Marino is a predominantly Catholic state, though Catholicism is not an established religion. Over 97% of the population profess the Catholic faith, and approximately half of those practice it. There is no episcopal see in San Marino, although its name is part of the present diocesan title. Historically, the various parishes in San Marino were divided between two Italian dioceses, mostly in the Diocese of Montefeltro, and partly in the Diocese of Rimini. In 1977, the border between Montefeltro and Rimini was readjusted so that all of San Marino fell within the diocese of Montefeltro. The bishop of Montefeltro-San Marino resides in Pennabilli, in Italy's province of Pesaro e Urbino. The country's high Roman Catholic majority can mainly be brought back to the country's founding, where Saint Marinus set up the first fortress to protect Christians from Roman persecution. The small state's culture has primarily remained Catholic ever since.