The Slavic Languages: The Use of the Cyrillic Alphabet

The Slavic languages belong to the Indo-European family of languages.  They are spoken in much of Central Europe, the Balkans, Eastern Europe and Northern Asia.  The amount of speakers tops 400 million persons approximately, among which are Russians, Bielorussians, Ukranians, Bulgarians, Macedonians, Serbs, Croats, Slovenians, Poles, Czechs, and Slovaks.
They use the Cyrillic alphabet (under the influence of the Orthodox Church) and the Roman alphabet (under the influence of the Catholic Church).  In times of old, they also used the Arabic and Glagolitic alphabets.  In certain parts of Europe there were groups of people without their own alphabets, having to import one or another; this is the case of the Slavs, who were provided with an alphabet to evangelize them.
The principal diversification of the common Slavic language occurred, coincidentally, at the same time that Latin disintegrated into the Romance languages.
The Slavic languages are directly related to the Baltic language group, but also share certain linguistic innovations with other groups of Indo-European languages, such as the Indo-Iranian and Armenian groups.