The regional unit is mountainous with a pronounced continental climate, characterised by cold winters and hot summers.

[3] The rural areas of Kastoria province were multi–ethnic, as the north was largely, though not entirely populated by Slavic speakers, while the south mainly had Grecophones.

[12] Political categories from a nationalist perspective were used to describe ethnic groups or religious affiliations in the 1924 data by Greek authorities.

[4] Greek refugees arrived in the Kastoria area, while their settlement was limited by the lack of fertile land and the need for stable bilateral relations with Yugoslavia which also prevented mass Slavophone emigration.

[5] In Greek Macedonia, Kastoria province remained an area in the interwar period where Slavophones were a large part of the population.

[5] A 1925 study by the Greek 10th Army Division of Western Macedonia recorded 1,866 refugee families were settled in 28 villages within the Kastoria region.

[13] Greek refugee families in Kastoria prefecture were from East Thrace (41), Asia Minor (441), Pontus (1,417), the Caucasus (23) and unidentified locations (9) in 1926.

[16] A refugee committee report (1942) from Bulgarian occupied northern Greece using League of Nations data covering 1913 to 1928 stated the numbers of Slav Macedonian emigrants from Kastoria district to Bulgaria were 4,070.

[3] The Greek ministers for Military Affairs, Justice and the Interior ordered a census (1945) of citizens with "Bulgarian sentiments" who numbered 11,380 in Kastoria Prefecture.

[22] Information supplied to diplomat Dimitrios Bitsios and academic Evangelos Kofos by local representatives in 1965 estimated Slavophones in Kastoria district numbered 40,000.

[23] Slavophones were concentrated in certain areas within the prefecture and a significant small part of the population had knowledge of and used the Macedonian language, being aware of its cultural value.