Seeing as how Greek and Southern European missionaries went north to Russia and spread their faith there, and considering the cultural contacts between the (eastern) Norse people and east Europeans and Byzantines, where there ever any attempts by Greek or other people to convert the Vikings to orthodoxy?
The Vikings that expanded east into the Volga and other Russian river systems, called the Varangians founded the kingdom of Kievian Rus which would develop close ties with the Byzantine empire and accepted Orthodox conversion in the year 867 AD.