Armenian, an Indo-European language, was unwritten before the fifth century AD. After Christianity was proclaimed as the official religion in the early fourth century, the churches had to use Greek and Syrian religious works. Almost a century later, Sahak the Great, the Katholikos (head) of the Armenian Church, and Vramshapuh, the Arsacid king, jointly ordered the monk Mesrop Mashtots‘ to devise an Armenian alphabet. The alphabet that Mesrop Mashtots‘ created around 406 consisted of thirty-six letters. The letters Օ (ō) and Ֆ (f ) were added in mediaeval times, raising the number of letters to thirty-eight. The alphabet and its forms are featured in this 1856 textbook published by the Armenian community of St. Petersburg, Russia.