It is argued here that eddic poetry, where oaths were sworn on items like rings and weapons, can provide insight into practices of swearing oaths in the real world of the Vikings. It is problematic that the earliest surviving manuscripts of the eddic poems date from the late 13^th century, but other sources, including written sources from outside Scandinavia, evidence the existence of such oaths. The workings of the oaths rested on beliefs that the gods, and the items invoked in the process, would take vengeance on oath-breakers. When Christianity arrived, the procedure continued, but in a new wrapping: around the year 1000 A.D., God replaced the gods, items like weapons and rings disappeared from the procedure, and instead, people swore on items like the Bible or the cross. This transformation of a legal procedure rooted in heathen times into a procedure accepted in a Christian context seems to have taken place among the other Germanic peoples and Celts who converted to Christianity centuries before the new religion reached Scandinavia.