After a couple centuries of strife, Rome's Western Empire formally collapsed in A.D. 476, when its last emperor, Romulus Augustus, took early retirement in the Campanian countryside. But the conversion of barbarian leaders to Christianity ensured that glass played an ongoing and important role in the lighting of ecclesiastical buildings.
Many of the lamp shapes used in northwestern Europe in early Medieval times derived directly from Roman prototypes. For example, tucked away beneath the one limb of the cross-bar letter "F" in the illuminated lettering of the Moutier Grandval Bible, is a cross-shaped candelabrum with three glass lamps. The outer ones recall the simple Roman conical lamp of the Constantine era, while the central one is reminiscent of the bowl-type lamps that came into favor during the 5th century A.D.
The "bowl-and-stem" lamp form was particularly enduring, showing up as late as A.D. 1380 in the Tapestry of the Apocalypse of Angers that was made for the Duke Louis I of Anjou, and bequeathed a century later to Angers Cathedral by the French king René.