Scotland a territorial parish structure, with every community in Scotland having a local congregation. Scotland also has a significant Roman Catholic population, 19% professing that faith, particularly in Greater Glasgow and the north-west. After the Reformation, Roman Catholicism in Scotland continued in the Highlands and some western islands like Uist and Barra, and it was strengthened during the 19th century by immigration from Ireland. Other Christian denominations in Scotland include the Free Church of Scotland, and various other Presbyterian offshoots. Scotland's third largest church is the Scottish Episcopal Church. Islam is the largest non-Christian religion (estimated at around 75,000, which is
Scotland in the Late Middle Ages would have been relatively evenly spread over the kingdom, with roughly half living north of the Tay. Perhaps ten per cent of the population lived in one of fifty burghs that existed at the beginning of the period, mainly in the east and south. It has been suggested that they would have had a mean population of about 2,000, but many would be much smaller than 1,000 and the largest, Edinburgh, probably had a population of over 10,000 by the end of the era. Scotland is roughly half the size of England and Wales, but has only between a fifth