varies The gusli (Russian: гусли, IPA: [ˈɡuslʲɪ]) is the oldest East Slavic multi-string plucked instrument, belonging to the zither family, due to its strings being parallel to its resonance board.

It has its relatives in Europe and throughout the world: kantele in Finland, kannel in Estonia, kanklės in Lithuania, kokles in Latvia, Zither in Germany, citera in the Czech Republic, and psalterium in France.

The term gusli derives from the verb *gǫsti (make sound, howl, play music) with the suffix *slь (from Proto-Indo-European *-trom).

Vertkov states that the first mentions of the gusli date back to 591 AD to a treatise by the Greek historian Theophylact Simocatta which describes the instrument being used by Slavs from the area of the later Kievan Rus' kingdom.

[citation needed] During the war at the end of the 6th century, the Greeks took Slavonic prisoners and found a musical instrument named the Gusli.

[citation needed] The gusli are thought to have been the instrument used by the legendary Boyan (a singer of tales) described in the Lay of Igor's campaign.

A number of Slavic folk music instruments have names which are related to Gusli such as the Czech violin housle and the Balkan one-stringed fiddle gusle.