The thief stole a typewriter used by poet and national figure Rainis (Jānis Pliekšāns) as well as an inkpot and dip pen that belonged to the man who is easily the most influential figure in Latvian letters.
It is estimated the objects are worth around €14,000.
The cameras at the museum caught a young man loading the artifacts into his bag and going away.
Anyone who recognizes the man are asked to report to the police.