On this day (12 May 922), Ahmad ibn Fadlan, a scholar of Islamic law sent as an ambassador by the Abbasid caliphate, reached the land of the Volga Vikings. His account is one of the earliest surviving records about the Vikings.

His accounts: http://www.amazon.com/Ibn-Fadlan-Land-Darkness-Travellers/dp/0140455078/ref=sr_1_1?ie=UTF8&qid=1431438678&sr=8-1&keywords=ibn+fadlan