Direct observation. This is because the anecdotal fallacy is a logical fallacy and says that isolated events are not adequate pieces of evidence. It must be a well-documented case to be evidence.
Anglo-Saxons liked to gather in the lord's great hall, to eat and drink, and to listen to songs and stories. They loved tales about brave warriors and their adventures. A favourite story told how Beowulf, a heroic prince, kills the fierce man-eating monster Grendel, and Grendel's equally horrid mother. The story of Beowulf was first written down in the 8th-9th centuries, but long before that the story was told around the fire. The storyteller played music to accompany the songs and poems, on a small harp or on another stringed instrument called a lyre
