An epic is a lengthy narrative poem recounting the extraordinary deeds of legendary heroes, often involving gods or superhuman forces, and originally composed in preliterate societies as oral tradition where bards memorized the verses word-for-word. The oldest known epic is the Epic of Gilgamesh (c. 2500–1300 BCE) from ancient Sumer, while the longest is the ancient Indian Mahabharata (c. 3rd century BC–3rd century AD), containing over 1.8 million words—roughly twice the length of the Persian Shahnameh and ten times the combined length of the Iliad and Odyssey. Western culture's foundational epics include Homer's Iliad and Odyssey, Virgil's Aeneid, and the Old English Beowulf, which have inspired derivative genres like epic films. Famous epics span the globe, from the Sanskrit Rāmāyaṇa and the Finnish Kalevala to Dante's Divine Comedy and modern works like Derek Walcott's Omeros and William Carlos Williams's Paterson. The term derives from the Greek epikos, meaning 'word, story, poem', and 20th-century scholars like Milman Parry and Albert Lord demonstrated that oral epics were built from short, equal-status episodes for easy memorization, a style later adapted by writing poets such as Virgil, Dante, and Milton.