Anglo-Saxon legal concepts, particularly the principles of feud and dispute resolution, have a demonstrable influence on the themes and narrative structure of Beowulf. Beowulf's three main monster fights, with Grendel, Grendel's mother and the dragon, may be legally analyzed to determine why the hero has greater difficulties in each fight--in each, the hero's antagonist has a progressively stronger legal right to resistance, from the negligible legal position of Grendel up through the very ambiguous legal rights of the dragon in the final fight. An extremely important influence on each fight is the Anglo-Saxon concept of guardianship over place, or mund, which gives a legal dimension to the poem's emphasis on the sacrosanct and inviolable nature of the "close"--the great meadhall Heorot, or the gudsele ("battle-hall") of the Grendel kin or the eordsele ("earth-hall") of the dragon--and the relative justice of armed forays into such spaces.