Exact numbers of communicants are uncertain, given the illegal status of Catholicism. In 1755 it was estimated that there were some 16,500 communicants, mainly in the north and west.J. D. Mackie, B. Lenman and G. Parker, A History of Scotland (London: Penguin, 1991), , pp. 298–9. In 1764, "the total Catholic population in Scotland would have been about 33,000 or 2.6% of the total population. Of these 23,000 were in the Highlands". Another estimate for 1764 is of 13,166 Catholics in the Highlands, perhaps a quarter of whom had emigrated by 1790,Lynch, Michael,Scotland, A New History (Pimlico: London, 1992), p. 367. and another source estimates Catholics as perhaps 10% of the population.
