Bjarni Hurjulfson. No kidding. The sagas of King Olaf, older than the other Norsement sagas, give credit to Bjarni Hurjulfson as early as 985. Ericson’s sagas may have caught the Norse imagination more, because he went as a Christian evangelist in the year 1000 AD.
And to this day Norsemen in New Foundland rub and kiss the Bjarni Stone for luck.