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
Geography of Scotland in the early modern era life of their displaced workers, enclosures led to unemployment and forced migrations to the burghs or abroad. There are almost no reliable sources with which to track the population of Scotland before the late seventeenth century. Estimates based on English records suggest that by the end of the Middle Ages the Black Death and subsequent recurring outbreaks of the plague may have caused the population of Scotland to fall as low as half a million people. Price inflation, which generally reflects growing demand for food, suggests that this probably expanded in the first half of the sixteenth century, levelling off