Economically the military presence was important with workshops growing up to supply the needs of the 5,000 troops garrisoned there and in its early stages York operated a command economy. Production included military pottery until the mid-third century; military tile kilns have been found in the Aldwark-Peasholme Green area, glassworking at Coppergate, metalworks and leatherworks producing military equipment in Tanner Row. New trading opportunities led local people to create a permanent civilian settlement on the south-west bank of the River Ouse opposite the fortress. By 237 it had been made a colonia one of only four in Britain and the others were founded for retired soldiers. York was self-governing, with a council made up of rich locals, including merchants, and veteran soldiers.