When one looks at the ruins of the castles of the Middle Ages, one can hardly see how an enemy ever had the courage to attempt to capture one of them. Indeed, if a foe could spare the time and the men, it was usually easier and cheaper to keep close watch of it until the inmates were starved into a surrender. No matter how full of food the storehouses might be, it would give out some time; and if no assistance came from outside, the castle would have to yield. If an attempt to subdue a castle was made, however, there were three common methods of attack. One was to force a way in through a gate if possible; a second, to get to the top of the protecting wall and overpower the defenders; and a third, to undermine the walls. If the wall was neither too high nor too well guarded, the enemy could sometimes set up scaling ladders with their iron hooks and make a furious attack upon the defenders at the top, which they resisted as furiously with crowbars, and bills and boar spears. The best way to get to the top of a high and well-defended wall was to use the movable tower. This was a wooden shed several stories high and set upon rollers. When this was to be used, there was a busy running to and fro to collect turf and trunks of trees to throw into the moat. As soon as enough of these materials had been collected to choke up the moat and make a roadway across it, the great tower was rolled cumbrously across the moat and up to the wall. It was filled with men, and the moment that it was near enough to the rampart, a drawbridge was dropped from its upper story to the top of the wall. Over this bridge rushed the besiegers, and a terrible contest was carried on. Of course the defenders did not sit quietly while the tower was being moved up. They threw upon it what was called Greek fire in the hope of setting it ablaze. Greek fire is thought to have been made of asphalt, nitre, and sulphur. Wherever it was thrown, there it stuck. It did little damage to these towers, however, for their makers had covered them carefully with plates of metal or with raw hides. Storms of arrows were shot by both sides; but the men in the tower were so well protected by its walls that little harm was done them. When the tower was in place and the bridge down, the besiegers had one great advantage, for they could march out a whole column from the tower, while the defenders had seldom room on the wall for more than a thin line.

A third way of attacking a castle was by attempting to undermine the walls. If these rested upon so rocky a foundation as that of the "Saucy Castle," the matter was far more difficult; but if the ground was soft, a mine, or passage underground, could be begun at some distance away and dug under the very base of the wall. Beams were put in to support the wall, and straw, twigs, and dry wood were heaped up under them. The miners set this on fire and crept out of the hole as fast as possible. As soon as the beams were burned through, the wall above them generally fell, and through the breach the besiegers rushed in with good hope of winning a victory. Mining did not always go on so smoothly, however, for it often happened that some one within the castle had ears so quick that he heard noises underground and what was being done. Then a counter-mine was dug from within outward in the hope of intercepting the other mine. The two passages sometimes met, and the fighting between the men underground was most furious and savage.

If the castle had a firm rocky foundation, the only possible way to undermine the wall was by the use of the pickaxe. This was not easy when the defenders behind the parapets were shooting arrows and great stones and dropping boiling water or oil or melted lead down through the openings between the machicolations; and if it was to succeed, there must be some sort of protection for the men with the pickaxes. This protection was called the "cat," or in some places the "rat." It was shaped like a long, narrow house with side walls. The roof sloped sharply, so that the heavy stones and beams that would be thrown upon it from the top of the wall might roll off harmlessly. To protect it from fire, it was often covered with iron, and over this raw hides or wet earth was laid. Then, too, men within the structure were always on guard with long forks or poles whose ends were covered with pieces of wet blanket to thrust off firebrands. This was built in some place out of range of the arrows and stones and then moved up close to the wall. Under its shelter men could work in safety. They had a valuable tool in what was known as a "bosson." This was a battering ram, a long, heavy beam with an iron head. It was on wheels, and when the besiegers rolled it up and dashed it against the wall, it struck with terrific force. The defenders on the top of the wall tried to break its head off by dropping heavy stones and timbers upon it; but the besiegers leaned strong poles against the wall in such a way that these slid off harmlessly. The attempt to set it afire was usually hopeless, for it was kept thoroughly wet and was covered with mud. Sometimes, however, a narrow tunnel was dug as quietly as possible from within the fort out under the cat, and a barrel or two of Greek fire slipped beneath it. Then the defenders on the wall watched eagerly to see the flames burst out. They might well count the moments, for at any instant the stone work under their feet might crumble.

All this time both besiegers and defenders were constantly firing arrows at each other by hand and also by machines called "balistas" which were like immense cross-bows and shot great arrows and javelins with tremendous force. To protect themselves from these the besiegers used bucklers and also a sort of screen called a "mantelet" which they moved before them on wheels. In the screen was a narrow slit through which they could send back a return fire. In the fourteenth century cannon were used to some extent, but they could fire only three or four shots an hour and had an unpleasant custom of exploding. Outside a fort, they were of some little value; but when the besieged ventured to mount them on the walls, the chief damage done was to their owners. Their recoil loosened the stones of the wall and frequently the cannon ingloriously rolled off. The most important machines were those for throwing stones, and these as well as the balistas were used by both besiegers and besieged. They were exceedingly powerful. Some of them could hurl for six hundred feet a stone weighing three hundred pounds. If they could only have worked rapidly, they would have done an immense amount of damage; but it took several days to set one up, and the best of them could throw only a few stones in an hour. Moreover, it was impossible to take accurate aim. One of these machines was called a trébuchet. It consisted of two uprights connected at the top by a bar. Resting on the bar was a ponderous beam. The shorter arm of this beam was heavily weighted; by using much force, the longer arm was slowly pulled down to the ground, and in a sort of sling fastened to it a great stone was placed or perhaps a barrel of Greek fire. Then it was suddenly let go. The short arm dropped, and the stone was hurled with tremendous power. There were other machines, the mangonel, catapult, espringal, etc., but they were not very dissimilar, and most of them resembled in principle either the balista or the trébuchet.