History of glass
The history of glass-making dates back to at least 3600 years ago in Mesopotamia. However, they may have been producing second-rate copies of glass objects from Egypt, where this complex craft originated. Other archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or Egypt. The earliest known glass objects, of the mid second millennium BC, were beads, perhaps initially created as the accidental by-products of metal-working (slags) or during the production of faience, a pre-glass vitreous material made by a process similar to glazing. Glass products remained a luxury until the disasters that overtook the late Bronze Age civilizations seemingly brought glass-making to a halt.
Engraving
However the use of glass engraving, usually using a wheel, to cut decorative scenes or figures into glass vessels, in imitation of hardstone carvings, appears as early as the first century AD, continuing into the fourth century CE at urban centers such as Cologne and Rome, and appears to have ceased sometime in the fifth century. Decoration was first based on Greek mythology, before hunting and circus scenes became popular, as well as imagery drawn from the Old and New Testament. It appears to have been used to mimic the appearance of precious metal wares during the same period, including the application of gold leaf, and could be cut free-hand or with lathes. As many as twenty separate stylistic workshops have been identified, and it seems likely that the engraver and vessel producer were separate craftsmen.