When do the oldest written records of the Czech language date from?

The oldest written records of the Czech language, specifically Czech glosses appearing in Latin and German texts, date back to the 12th century. While Old Church Slavonic was developed in the 9th century, Latin became the liturgical language in Bohemia in 1097, with its script adopted for what would evolve into the Czech language. The earliest preserved texts written entirely in Czech, primarily hymns, were created in the late 13th century. The period from the 11th to the 14th century is known as the Old Czech period, during which the language was not yet standardized.12