Moreover, the political circumstances of France were eminently favourable to the construction of great military works. The great duchies and scarcely subordinate kingdoms which afterwards composed the French monarchy were, in the eleventh and twelfth centuries, independent states, each with an open frontier needing defences, and with a brave and wealthy baronage very able and very willing to supply them. Hence France contains within its present borders not only cities of Roman origin and celebrated under the immediate successors of the Romans, but the remains of the castle-palaces of the dukes and barons of Normandy and Brittany; of Burgundy, Provence, Navarre, Flanders, Anjou, and many a lesser province; and he is but little qualified to judge of castles or of fortified mediæval cities who is unacquainted with Arques, or Falaise, or Loches; Coucy or Château-Gaillard, or Etampes; Carcassonne, Avignon, Villeneuve, or Beaucaire, or the splendid restoration of Pierrefonds. The possession of these great works has drawn forth, though tardily, a few writers capable of comprehending and describing them. Those in Normandy are the subject of the well-known lectures of M. de Caumont, delivered at Caen in 1830 and published in 1835. They contain a very interesting section on military works, with plans and elevations which, though roughly executed and on a small scale, are valuable; his descriptions are clear, and his conclusions generally sound. Others, before M. de Caumont, have described particular structures, but he seems to have been the first to attempt a general classification based upon a critical examination of the examples in his own province. Of detached writings, monographs, may be mentioned those of M. Deville upon Château-Gaillard, Tancarville, and Arques, published in 1828, 1834, and 1839. The first is particularly strong in its history of the castle and of its famous siege, and the last excellent both in history and description; and all three are accompanied by clear ground-plans.