The excavations by the Northampton Development Corporation's Archaeological Unit of the English City of Northampton has revealed new information about the early leather tanning industry that flourished there in the 16th and 17th centuries. The article gives the history of the tanning process as well as a detailed account of how hides were tanned in Northampton. Chemical analysis of the contents of clay-lined pits helped identify the functions of individual pits. -- AATA