Exhibit Antiques has dated this piece to the 1750s.
England, c1760. Period of George III.
Condition
Excellent, age-related wear as shown, no chips cracks or restoration. Small slag seed from manufacture in the foot, as to be expected.
Dimensions

Height: 12.5cm Rim diameter: 4.6cm Foot diameter: 5.9cm.
Technical Description
An English lead 18th-century opaque twist gin glass.
A conical foot with a rough pontil.

Historical Relevance
A fine example with a relatively small bowl which was probably used for Gin rather than wine. The English parliament passed various acts from 1729 through 1751 designed to control the consumption of gin and curb the epidemic of extreme drunkenness and the overconsumption of gin. Although the smaller bowl may point to Gin usage there other similar acholic drinks that were available at that time which would have suited the glass...most of which we today would find rather vile for our 21st-century palets.
In a historical context, this glass was hand-blown around the time Blackfriars Bridge across the River Thames in London opened to traffic on the 16th of November 1769.
Exhibit Antiques has dated this piece to the 1750s.
Specialists in 18th & 19th century antique glass
You can view the stock and full dealer information on the Exhibit Antiques Profile Page