Green Glazed Jug, ead glazed earthenware, Made in Mill Green, Essex, England,14th century.

http://www.metmuseum.org/art/collection/search/651289

The speckled green glaze is typical of medieval ceramics from the kilns at Mill Green, about forty miles northeast of London. For about a century, beginning around 1270, potters there created tableware both for local use and for sale in the capital and at other locales within about a forty-mile radius, including Kent, Cambridge, and Hertfordshire. This jug’s thin walls reflect the skill of the ceramicist. The decorative accents—with raised ribs and incised lines—further suggest its use by a refined clientele.