[Illustration: TYPICAL CASTLE OF THE MIDDLE AGES
Nevertheless, this seemingly impenetrable fortress did not suffice. In the first place, superior methods of siege warfare were developing: the stoutest fortifications could be cracked.[4] In the next place, if the donjon were hard to enter, it was almost equally hard to sally forth from it. No rapid sortie could be made from the door in the second story; the defense must be wholly passive. Finally, this stark masonry tower was a most uncomfortable place, with its cavernous "halls" barely lighted by tiny loopholes, frigid in winter, stifling in summer, unsanitary--in short, almost intolerable for habitation by a large body of men. After the First Crusade (1094-99) numerous cavaliers came home with great tales of the fortresses of the Byzantines and the Saracens. During the twelfth century, consequently, castle architecture underwent a remarkable transformation. Richard the Lion Hearted built Château Gaillard in Normandy. His mighty rival, Philip Augustus, built the famous Louvre to dominate Paris, and erected other new-style castles with cylindrical towers at Montargis, Poissy, Dourges, and elsewhere. Already by 1220 the plans are being drawn for a great castle at Coucy (built between 1223 and 1230) which is to be almost a model for all subsequent fortress builders, until the advent of gunpowder.
[Sidenote: Castle Rebuilt Scientifically]
Baron Garnier, whatever his crimes, had certainly understood the art of war. He rebuilt St. Aliquis in a thoroughly scientific manner, employing a learned masterbuilder and "sage," an elderly Fleming who had seen the best fortifications of the Infidels and had lived long in those famous Syrian-Christian fortresses like Krak des Chevaliers, which by the mere excellence of construction had enabled small garrisons of western "Franks" to defy the full power of Saladin. Instead of a mere ditch, palisade, and then a single vast tower, St. Aliquis has consequently become a huge complex of defenses within defenses, each line of resistance a little harder to penetrate and with every outwork commanded by an inner fortification. If at last you come to the central donjon, it still looms up above you--defiant and formidable, and you can have your fill of desperate fighting, only perhaps to be bloodily repulsed in the end. Of course, the donjon can indeed be starved out, but it is not very often that any enemy of St. Aliquis will have resources and persistence enough to keep his troops together until the castle supplies are exhausted. He must either get possession pretty quickly or not at all--and Garnier's Fleming certainly took pains he should not get in quickly!