This thesis seeks to answer the question of why medieval physicians “forgot” efficacious medical treatments developed by the Anglo-Saxons and how Anglo-Saxon medical texts fell into obscurity. This thesis is largely based on the 2015 study of Freya Harrison et al., which replicated a tenth-century Anglo-Saxon eyesalve and found that it produced antistaphylococcal activity similar to that of modern antibiotics. Following an examination of the historiography, primary texts, and historical context, this thesis concludes that Anglo-Saxon medical texts, regardless of what useful remedies they contained, were forgotten primarily due to reasons of language: the obsolescence of Old English following the Norman Conquest, and the dominance of Latin in the University-based medical schools in medieval Europe.