Final answer:
Beowulf cutting off Grendel's head symbolizes the complete defeat and dishonor of evil, showcasing Beowulf's heroism and aligning with historical depictions of victors decapitating their foes to illustrate dominance and victory.
Step-by-step explanation:
Beowulf cutting off Grendel's head symbolizes the triumph of good over evil, the hero's valor, and the finality of Grendel's defeat. In history and literature, decapitation often represents the ultimate defeat and dishonor of an enemy. For instance, the great warriors depicted in artifacts such as the Harald Stone and the imagery used on the Jelling Stones illustrate the deep symbolic meaning of conquering one's foes as seen through decapitations and the removal of symbols of power, such as armor. Much like St George slaying the dragon which symbolizes cosmic evil, Beowulf's act carries a similar symbolic meaning in vanquishing monstrous evils. Additionally, as historical figures are often shown in a grand scale to symbolize their power and importance, Beowulf's ability to defeat and behead Grendel emphasizes his strength, bravery, and standing as a hero.