 Coptic more obviously displays a number of regional dialects that were in use from the coast of the Mediterranean Sea in northern Egypt, south into Nubia, and in the western oases.However, while many of these dialects reflect actual regional linguistic (namely phonological and some lexical) variation, they mostly reflect localised orthographic traditions with very little grammatical differences.Sahidic (also known as Thebaic) is the dialect in which most known Coptic texts are written, and was the leading dialect in the pre-Islamic period.