English: This map represents the distribution of Catholics in Albania around 1900.

Main sources: 1. This map (look at the one on the right, the one on the left is about population density not religion): [1]. Data ultimately derived from the 1918 Albanian census. Sadly, because the census was taken at a time of political uncertainty, much of the South and East were not included, and thus the data is unavailable.

2. Gruber, Siegried. Regional variation in marriage patterns in Albania at the beginning of the 20th century. Data ultimately derived from the same source above (albeit with slight differences in certain provinces), and from there ultimately from the 1918 census. Link: www-gewi.uni-graz.at/seiner/marriage_patterns.html (go to map 6).

Note: Uniate Albanians are theoretically counted as Catholics here. What this actually means in practice, I don't know, as I haven't yet gotten my hands on stats of Uniates by province for the era.