Bankside

The brothels behind the phrase were licensed by a bishop.

Bankside is the Southwark riverbank opposite the City of London, outside the city's jurisdiction, where brothels called the stews operated from the Middle Ages. Much of the ground belonged to the Bishop of Winchester, and the women working there were known as Winchester geese. The slang outlived the trade and was still being recorded by Farmer and Henley in the nineteenth century.