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 married Margaret of Denmark, receiving the Orkney Islands and the Shetland Islands in payment of her dowry. However, in 1482 Berwick, a border fortress and the largest port in medieval Scotland, fell to the English once again, for what was to be the final change of hands. Because medieval Scotland lacked the intrusive government and growing bureaucracy that can be found in contemporaneous England, there is very little evidence on which to base reliable estimates of population before the early 18th century. On the basis that it had roughly a sixth of the farmable land of England, it has been