Alexander the Great conquered Egypt in 332 B.C. He established the city of Alexandria. After his death, in 323 BC, his empire was divided among his generals. Egypt was given to Ptolemy I Soter. However, Greek did not manage to impose itself in Egypt, for Egyptian (Demotic at this point, but later called Coptic) continued to be the language of the masses. It also managed to influence Greek. Coptic language flourished in Egypt until about 1000 A.D., by which time it had been replaced by Arabic as the language of daily life in Egypt. After the Arab conquest of Egypt in the 7th century A.D., the use of Coptic survived in the administrative structure of the government for some decades. After the 11th century A.D., Arabic replaced Greek and Coptic as the principal language of Alexandria. Coptic language ceased to be widely spoken in Lower Egypt after the 10th century, and in Upper Egypt after the 15th century.
Why learn Coptic?
Almost all the best commentaries and biblical studies require a knowledge of Greek, Hebrew, Aramaic, Syriac, Latin, Coptic, and Arabic. The Coptic tradition states that the first Egyptian to be converted by Mark the Evangelist was Anianus. About 1/4 of the Sahidic Coptic New Testament word list is Greco-Coptic (i.e. words adopted from Greek). The liturgy of the present day Coptic Orthodox Church in Egypt is written in a mixture of Arabic, Greek, and Bohairic Coptic dialect.