3. The rise of towns and the growth of commerce. We must not, however, think of commerce as if it had been first brought by the Normans. There had been roads and coins in Roman times. The Danes had been traders, probably, before they became pirates and invaders. Timber, millstones, cattle, coarse cloth, and arrow-heads crossed the Severn eastwards before the Normans saw it; and corn was carried westward. There were close relations, political and commercial, between Wales and Ireland from very early times. But the Norman and English Conquests revived and quickened trade. Towns rose, regular markets were established, and the barons who took tolls protected the merchants who paid them. Every baron had a castle, every castle needed a walled town, and a town cannot live except by trade. In the town the baron did not ask a Welshman whether he had been free or serf; the townsmen were strangers, and they welcomed the serf who came to work. 4. The monk and the friar. The bard was a freeman born, a skilled weaver of courteous phrases, not a churlish _taeog_. The monk or friar might be a serf. They worked like serfs, and ennobled labour. The Church condemned serfdom, and we find chapters giving their serfs freedom. 5. The Scotch and French wars of the English kings gave employment to hosts of bowmen and of men-at-arms, and to the numerous attendants required to look after the horses by means of which the army moved. The greater use of infantry after the reign of Edward I. caused a greater demand for the peasant; and the use of the cheap long-bow gave him a value in war. There were five thousand Welsh archers and spearmen on the field of Cressy. In these and other ways the serf was becoming free. You would expect a gradual, almost unconscious struggle, between the serf and his lord for political power. The struggle came, but it was conscious and very fierce. It was brought about by a terrible pestilence, known as the Black Death. This plague came slowly and steadily from the East; in 1348 it reached Bristol, and it probably swept away one half of the people of the towns of Wales. It was not the towns alone that it visited; it came to the mountain glens as well. It was a most deadly disease. It killed, for one thing, because people believed that they would die. They saw the dark spots on the skin before they became feverish; they recognised the black mark of the Death and they gave themselves up for lost. Labourers became very scarce. They claimed higher wages. The lords tried to drag them back into serfdom; they tried to force them by law to take the old wage. On both sides of the Severn the labourers took arms, and waged war against their lords. The peasant war in England is called the Peasant Revolt; the peasant war in Wales is sometimes called the revolt of Owen Glendower.