The Slavic Alphabet is also known as the Cyrillic Alphabet, which consists of 8 letters. It is used by many languages in Eastern Europe and Central Asia, including Russian, Ukrainian, Bulgarian, Serbian, and Belarusian. The Cyrillic Alphabet was developed in the 9th century AD by two Greek missionaries, Saint Cyril and Saint Methodius. It is based on the Greek alphabet, with some additional letters to represent sounds not found in Greek.