A medieval sketch from Novgorod

The usual writing medium in the Russian North during the 13th century was birch bark. One of the most important centers of the "Rus" people in that period was Novgorod, and the inhabitants generated a lot of commercial, religious, and perhaps personal documents.

Thanks to the vast supplies of birch trees there is a lot of work for archaeologists. I've never heard how this trove compares to the Cairo Geniza, but perhaps I'll look.

The image above comes from Live Science which often includes neat stuff.

The explanation of this document is that it was written by a 13th-century boy named Onfim who got bored with his schoolwork and started drawing on some. See Wikipedia for more on Onfrim.