From archaeological and literary study, the origins of stained glass can be placed at a hitherto unspecified time between Late Antiquity and the early Middle Ages. The absence of early medieval stained-glass windows in situ has recently been offset by a greater number of archaeological finds of stained-glass fragments dating, for the most part, to the seventh and eighth centuries ce. Precursors have often been identified in glass opus sectile compositions, imitating the marble sectilia widely seen in the Roman world. As an emerging medium, however – though possibly inspired by Mediterranean practices – stained glass surpassed its models. The new medium had to come up with a new aesthetic, one rooted in anticlassical traditions and expressed in artistic media such as enamels and cloisonné jewelry-making, that enhanced light and color. The article examines the emergence of stained glass in relation to the interactions of classical and anticlassical traditions, the diffusion of old and new media and techniques in a (no longer?) globalized late antique world. Parallels can also be drawn with literary writings by Sidonius Apollinaris, Gregory of Tours, and Venantius Fortunatus, as well as with the so-called Hisperic aesthetics and literature and early medieval theology and exegesis.