Christianity is the main religion practised in the city. Aberdeen's largest denominations are the Church of Scotland (through the Presbytery of Aberdeen) and the Roman Catholic Church, both with numerous churches across the city, with the Scottish Episcopal Church having the third-largest number. The most recent census in 2001 showed that Aberdeen has the highest proportion of non-religious residents of any city in Scotland, with nearly 43% of citizens claiming to have no religion and several former churches in the city have been converted into bars and restaurants. In the Middle Ages, the Kirk of St Nicholas was the only burgh kirk and one of Scotland's largest parish churches. Like a number of other Scottish kirks, it was subdivided after the Reformation, in this case into the East and West churches. At this time, the city also was home to houses of the Carmelites (Whitefriars) and Franciscans (Greyfriars), the latter of which surviving in modified form as the chapel of Marischal College as late as the early 20th century.