History and migration of the Slavic peoples and their language/s

The homeland of the Slavic peoples was originally in the area near to the present town of Pripyat, between Belarus and Ukraine. It was from here that, from the 500s, the Slavic peoples spread westwards and southwards (and also in a north-easterly direction). For example, according to Constantine VII Porphyrogennetos of Constantinople, the ancestors of the Croats and Serbs settled in the area now known as Bavaria, later relocating to their present homeland in the Balkans. What became the Moravian people settled in what is now Czechia, and in the early 800s formed the first Slavic state (Great Moravia) with its capital in Velihrad. Other Slavic tribes migrated as far south as what is now Greece in the Empire of Constantinople. 

Particularly in the early 800s (but also for some time before that), the Empire of Constantinople reclaimed territories settled by Slavs, re-establishing government control and re-introducing Greek language and the Orthodox Christian faith. This is known as the Balkan Reconquista. 

The Balkan Reconquista laid the groundwork for the later work by missionaries from Constantinople, drawing Slavic peoples into the cultural orbit of the Empire of Constantinople and the religious orbit of Eastern Orthodoxy. For example, in 862, the King of Great Moravia, Rastislav sent a request for missionaries to be sent to allow his people, recently converted to Christianity, to praise God in their own language. Cyril and Methodius were sent from Constantinople, and provided the Moravians with their own alphabet, called Glagolitic (see below). This was used to translate the Eastern Orthodox liturgy, the Bible and other Christian texts. Glagolitic was based on the Greek alphabet, but the letters looked quite different and additional letters were used to cater for phonemes (sounds), such as the "sh" sound, absent from the Greek language. In time Eastern Orthodoxy and the Glagolitic/Cyrillic literacy spread to the Kingdom of Bulgaria. Over a century later, in 988, the Rus civilisation based on Kyiv officially became Christian. Kyivan Rus is the origin of both modern-day Ukraine and modern-day Russia. 

Glagolitic was later simplified to produce what is now known as the Cyrillic alphabet. It is thought that Eastern Orthodox monk, Clement of Ohrid, was the creator of the simplified Cyrillic alphabet. 

The original Slavonic liturgy and the Cyrillic alphabet are still in use among Eastern Orthodox Slavs, however over time the respective day-to-day Slavic languages have developed and diverged. Slavonic languages are categorised into West Slavic (Czech, Slovak, Polish etc.), South Slavic (Croat, Serbian etc.) and East Slavic (Ukrainian, Russian etc.). Slavic peoples who have traditionally belonged to the western Catholic church use the Latin script. In Romania, an Eastern Orthodox country but with a Romance language (related to Latin, Italian etc.), also uses the Latin script. 

The most widely spoken of the Slavic languages is Russian, spoken by 250 million or more people worldwide. This evolved from the East Slavic language of Kyivan Rus (988) via the Middle Russian spoken at the time of Ivan the Terrible (1500s) to modern-day Russian which dates to the 1700s. An early representative of modern Russian was the author Karamzin.  

Through the influence of the Russian Empire and later USSR, various non-Slavic peoples such as the Kyrgyz and Mongolians, also use the Cyrillic script. In some cases, such as Uzbekistan, there has been a recent move from Cyrillic to the Latin script.