So far I have told you very little about war, except that a battle was fought and lost, or a castle built or taken. War has two sides--attack and defence. New ways of attacking and defending are continually devised. When the art of defence is more perfect than the art of attack, the world changes very little, for the strong can keep what he has gained. When the art of attack is the more perfect, new men have a better chance, and many changes are made. The chief source of defence was the castle, the chief weapon of attack was the long-bow. Wales contains the most perfect castles in this country; it is also the home of the long-bow. From 1066 to 1284 England and Wales were conquered, and the conquest was permanent because castles were built. From 1284 to 1461, England and Wales attacked other countries, and the weapon which gave them so many victories was the long-bow. I will tell you about the castles first, about the Norman castles and about the Edwardian castles. The Norman castle was a square keep, with walls of immense thickness, sometimes of 20 feet. But if the Norman had to build on the top of a hill or on the ruins of an old castle, he did not try to make the new castle square, but allowed its walls to take the form of the hill or of the old castle; and this kind of castle was called a shell keep. The outer and inner casing of the wall would be of dressed stone, the middle part was chiefly rubble. At first, if they had plenty of supplies, a very few men could hold a castle against an army as long as they liked. These were the castles built by the Norman invaders to retain their hold over the Welsh districts they conquered. But many ways of storming a castle were discovered. They could be scaled by means of tall ladders, especially in a stealthy night attack. Stones could be thrown over the walls by mangonels to annoy the garrison. Sometimes a wall could be brought down by a battering- ram. But the quickest and surest way was by mining. The miners worked their way to the wall, and then began to take some of the stones of the outer casing out, propping the wall up with beams of wood. When the hole was big enough, they filled it with firewood; they greased the beams well, they set fire to them and then retired to a safe distance to see what happened. When the great wall crashed down, the soldiers swarmed over it to beat down the resistance of the garrison. If ever you go to Abergavenny Castle, in the Vale of Usk, look at the cleft in the rock along which the daring besiegers once climbed. And if you go to the Vale of Towy, and see Dryslwyn Castle, remember that the wall once came down before the miners expected, and that many men were crushed. In order to prevent mining, many changes were made. Moats were dug round the castle, and filled with water. Brattices were made along the top of the towers, galleries through the floor of which the defenders could pour boiling pitch on the besiegers. The walls were built at such angles that a window, with archers posted behind it, could command each wall. Stronger towers were built--round towers with a coping at each storey, solid as a rock, which would crack and lean without falling; there is a leaning tower at Caerphilly Castle. One other way I must mention--the child or the wife of the castellan would be brought before the walls, and hanged before his eyes unless he opened the gates. The newer or Edwardian castles, those of the reigns of Henry III. and Edward I., are concentric--that is, there are several castles in one; so that the besiegers, when they had taken one castle, found themselves face to face with another, still stronger, perhaps, inside it. Of these castles, the most elaborate is the castle of Caerphilly, built by Gilbert de Clare, the Red Earl of Gloucester who helped Edward in the Welsh wars. And it was by means of these magnificent concentric castles--Conway, Beaumaris, Carnarvon, and Harlech--that Edward hoped to keep Wales. There are many kinds of bows. In war two were used--the cross-bow and the long-bow. The cross-bow was meant at first for the defence of towns, like Genoa or the towns of Castile. So strength was more important than lightness, and the archer had time to take aim. It was a bow on a cross piece of wood, along which the string was drawn back peg after peg by mechanism. The bow was then held to the breast, and the arrow let off. It was clumsy, heavy, and expensive. The long-bow was only one piece of sinewy yew, and a string. It was used at first for the chase, and the archer had to take instant aim. It was drawn to the ear, and it was a most deadly weapon when a strong arm had been trained to draw it. Its arrow could pick off a soldier at the top of the highest castle; it could pierce through an oak door three fingers thick; it could pin a mail-clad knight to his horse. It was this peasant weapon that brought the mailed knight down in battle. The home of the long-bow is the country between the Severn and the Wye. It was famous before, but it was first used with effect in the last Welsh wars. It was used to break the lines of the Snowdon lances and pikes, so that the mail-clad cavalry might dash in. But later on, the same bows were used to bring the nobles of France down. From the Welsh war on, archers and infantry became important; battles ceased to be what they had been so long--the shock of mail-clad knights meeting each other at full charge. The long-bow made noble and peasant equal on the field of battle. The revolution was made complete later on by gunpowder.