Cage cup

[1] Diatreta consist of an inner beaker and an outer cage or shell of decoration that stands out from the body of the cup, to which it is attached by short stems or shanks.

Some have a flange, or zone of projecting open-cut moulding, above the lower patterns and below the lettering (only illustrated here by the Cologne cup in the gallery).

[7] Since the first publication on the subject in 1680 it has mostly been accepted that the cage cups were made by cutting and grinding a blank vessel of solid thick glass, a laborious technique at which the Greeks and Romans were very experienced from their passion for hardstone carvings and engraved gems in semi-precious stones.

The fragment shows a pattern based on circles, that is very similar to the glass diatreta, suggesting that the same style may have been used in silver plate, though which came first is unknown.

[11] Some examples add difficulty to the manufacturing process by using different colours on the cage, like the Milan and Cologne cups, but most are plain glass, like those at Munich and Corning.

The Corning cup was certainly intended for suspension, as the copper alloy fittings were found with it; there is a round band fitting under the rim, and three pieces that are part chain and part rod, leading to a ring and single rod, and a variety of cups for three attachments,[12] very like a hanging basket in modern gardens, and an arrangement known to have been used for lamps by the Romans.

However the majority of finds of diatreta are from Roman sites along the Rhine, or near it, suggesting that they were produced in the area, perhaps at Augusta Treverorum, modern Trier.

This was the largest city of Roman Germany and the main residence of Constantine I for many years, coinciding with the period when the cups seem to have been made.

In 1959 a detailed account of the Lycurgus Cup was published by Donald Harden and Jocelyn Toynbee, which also discussed diatreta as a group, effectively for the first time.