When the Germans commanded the Ubii of Cologne to cast off the Roman yoke, and with their new freedom to resume their ancient manners, they insisted on the immediate demolition of the walls of the colony. "Postulamus a vobis, muros coloniae munimenta servitii detrahatis; etiam fera animalia, si clausa teneas, virtutis obliviscuntur." Tacitus Histories iv. 64.