Alphabet used for writing Old Church Slavonic that appeared in Moravia around 800 AD, and later spread to Slavic-speaking Roman Catholic communities on the Balkans. The script had two variants; rounded and square.

The script seems to have influenced the Cyrillic alphabet, which it was later supplanted by. Some of the letters for the specifically Slavic phonemes are similar or identical in the two scripts, and most of the remaining letters in the Cyrillic alphabet seem to have been taken from Greek.

Apart from that, the Glagolitic letters bear no resemblance to any other known alphabet. The origin of the Glagolitic alphabet is not clear, and remains a mystery today.