The upper town, built on the western incline of the plateau, contained two parish churches, I and K. A wooden bridge, with mills belonging to the castle, existed at L, another wooden bridge at M, and the Roman stone bridge at N.

On the right bank were several houses with gardens. At O the road along the plateau branched into two—one leading to the entrance of the abbey, the other to that of the castle. At P was a breadth of cultivated land, and at R the forest, which extended in a northerly direction more than two thousand paces. Of the ancient ramping wall of the Romans, S, and of the enclosure, T, there existed only heaps of débris. These remains, overgrown with vegetation, formed, nevertheless, an elevation which it was possible to defend.

This sketch of the general topography premised, we proceed to explain the dispositions adopted in the building of the new castle ([Fig. 36]). [11] At O existed a fosse, which was re-excavated. A barbican stood at A, entered on the left side.

FIG. 36.— THE CASTLE OF LA ROCHE PONT. 12TH CENTURY.

The main entrance of the castle, with its drawbridge, was necessarily placed at B. This gate had to be protected by two towers. Upon a part of the ancient Roman north front, five towers were planned, whose curtains were to join the two ancient towers, Y, which were repaired and re-crowned. A wide space, C, therefore necessarily remained behind this foremost defence. It was the bailey, a fore-court or outer-court, in which were laid out the chapel, E, promised to the abbot; stables, D; and outbuildings, F, upon a Roman ruin. At P was sunk a second fosse for the protection of the castle, whose gateway was disposed at G. A postern gave egress at H. The ancient Roman wall, M, received a new crowning, and three new towers were to add to its strength.

At I were laid the foundations of the donjon—partly on ancient masonry—a donjon defended by a chemise and ditch. The buildings designed for habitation were situated at K, with a chapel at I. At the extremities of the ditch, P, cuttings were contrived in the two Roman curtains, to intercept, if necessary, all communication between the defences of the bailey and those of the castle. This contrivance was also adopted for the two curtains abutting on the donjon.

The baron spent his whole time, ever since the decision come to by his nephew, with the master of the works, Alain of Troyes; while the workmen first called in cleared the ground and levelled the Roman ruins, and quantities of stone, sand, gravel, and timber were brought in, and the ditches and trenches for the foundations were excavated by the forced labour of the tenants.

The baron designed to erect opposite the plateau (the point of attack) a great front, slightly convex, to screen the projections, W. He wished to have a wide barbican in the middle of this front, in which to collect the troops intended for sorties, and to shelter them in case of retreat. He had observed that in all the good defences erected by the Christians in Syria the entrances were so disposed that the assailant was obliged to present his right flank to the defender—with good reason, since the left is protected by the shield or buckler. The position of the gate, C, of the castle had been the subject of considerable study and discussion on the part of the baron and his master of works. The latter wanted to place it parallel with the front, but the baron insisted on its forming a decided angle with the entrance of the bailey. The master of the works urged that the left-hand tower of this gate, G, would then form a projection insufficiently defended, and open to attack; but the baron maintained that if the besiegers endeavoured to attack or mine this tower, they would be commanded obliquely by the tower, R; that by giving sinuosities to this front of the castle all points of the bailey would be commanded; that the principal gate was thus well masked; that nothing more would be needed than to give a considerable thickness to the walls and a greater diameter to the entrance towers; and lastly, if the enemy succeeded in reducing the projecting tower on the right hand, a barricade might still be raised from S to T, and the defence prolonged, with the favourable consideration that if this tower of the salient were thrown down, the other would remain intact and would command the breach.