Fairs and markets were a vital part of the medieval economy, but a royal charter was needed for either, so they were highly profitable to the manors which had the right to hold them. The grant of Penkridge manor to the archbishop of Dublin included the right to hold an annual fair. This right was upheld for the Blund family by Edward I in 1278 and by Edward II in 1312. The date varied, but in the Middle Ages it fell around the end of September and lasted for seven or eight days. It began as a general fair but developed into a horse fair by the late 16th century.