Mostich (Bulgarian: Мостич, Old Bulgarian: МОСТИЧЬ) was a high-ranking official in the 10th-century First Bulgarian Empire, during the rule of Simeon I and Peter I. He bore the title of Ichirgu-boil and was most likely the commander of the state capital Preslav's garrison.
Mostich is known from a 10th-century Old Bulgarian epigraph in a church (now known as "Mostich's Church") in the Selishte area of Preslav, then the inner city of the Bulgarian capital. The text was discovered in 1952 by Professor Stancho Vaklinov and is preserved in the National Archaeological Museum. The inscription is Mostich's epitaph, indicating that he was buried in the church: his remains were also found, revealing that he was relatively short (165–170 cm). The text is notable for being the earliest source mentioning the word "Tsar".
It reads as follows:
|“||сьде лежитъ мо-
|“||Here lies Mostich, who was ichirgu-boil during Tsar Simeon and during Tsar Peter. At age 80, leaving his post and property behind, he became a monk and so finished his life.||”|
- "Надпис на чъргубиля Мостич от 10 век" (in Bulgarian). Bibliotheca Slavica. 2008-07-27.
- "Надгробен надпис на Мостич — втора четвърт на Х век /копие/" (in Bulgarian). Музей Преслав. 2008-07-27.