Large areas surrounding Penkridge were placed by the Norman kings under Forest Law, a savage penal code designed to protect the ecology and wildlife for the king's enjoyment. These areas were part of the Royal Forest of Cank or Cannock Chase and were known as Gailey Hay and Teddesley Hay. Forest law kept most of south Staffordshire in an economic straitjacket. Conflicts between the barons and kings in the 13th century forced a relaxation, starting with the first issue of the Forest Charter in 1217. So it was in Henry III's reign that Penkridge began to grow economically and probably in population. Local people began to create new fields, called assarts, by clearing the trees and scrub (still a capital crime), and Penkridge acquired an annual fair and weekly market.