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Birch bark document used for writing practice (and drawing) by a child, Novgorod Republic, 13th century AD
(media.piefed.social)
Fun fact: The discovery of these birch bark writings, and numerous caches like them, in the 1950s led to a radical re-examination of the literacy rates of Medieval Novgorod, since the birch bark writing provides evidence of lower/middle class writing on extremely mundane matters and in a vernacular tongue.
https://en.wikipedia.org/wiki/Birch_bark_manuscript#East_Slavic_manuscripts