The first written document mentioning the importance of Provins dates back to 802, when Charlemagne sent his "Missi Dominici" to the city (representatives of the king to supervise the administration). Fortified with city walls, the city became prosperous in the 12th and 13th centuries, under the Counts of Champagne, with its wool industry and its trading fairs. These were wholesale trading fairs, which were held three times a year and lasted for several weeks. Provins had its own currency, which was widely accepted.