The oldest inscription in Russian dates back to the 10th century

The inscription "гороухща" (“goroukhshcha”) on a clay pot is considered the oldest in Cyrillic. The find was discovered in 1949 during excavations near the village of Gnezdovo outside Smolensk. Scholars date it to the mid-10th century.

The meaning of ‘гороухща’ is not yet known for certain: it could be ‘горчица’ (‘mustard’), ‘горячее’ ([something] ‘hot’) or the name of the pot’s owner. However, it’s clear that this is precisely a Slavic word, as the letter ‘щ’ was not used anywhere else.