In advancing by the royal road from Lisbon, the allies ascended the Rio Mayor, until they reached the Ponte Seca, a raised causeway, eight hundred yards long, leading to the foot of the French position. On the right hand, as far as the Tagus, a flat sedgy marsh, not impassable, but difficult from deep water-cuts, covered the French left. On the other hand, the two streams of the Rio Mayor overflowing, presented a vast impassable sheet of water and marsh, covering the French right, and, in the centre, the causeway offered only a narrow line of approach, barred at the enemy’s end, by an abattis, and by a gentle eminence, with a battery looking down the whole length. To force this dangerous passage was only a preliminary step; the secondary range of hills was then to be carried before the great height of Santarem could be reached; finally, the town, with its old walls, offered a fourth point of resistance. In this formidable position, the second corps covered the rich plain of Golegao, which was occupied by Loison’s division of the sixth corps, placed there to watch the Tagus, and keep up the chain of communication with Punhete. On Reynier’s right, in a rugged country, which separated Santarem from the Monte Junta and the Sierra de Alcoberte, the eighth corps was posted; not in a continuous line with the second, but having the right pushed forward to Alcanhete, the centre at Pernes, and the left thrown back to Torres Novas, where Massena’s head-quarters were fixed. On the right of Alcanhete, the cavalry were disposed as far as Leiria, and the sixth corps was at Thomar, in reserve, having previously obliged Wilson’s militia to retire from the Zezere upon Espinhal. Massena thus enclosed an immense tract of fertile country; the plain of Golegao supplied him with maize and vegetables, and the Sierra de Alcoberte with cattle. He presented a formidable head to the allies at Santarem, commanded the road, by Leiria, to Coimbra, with the eighth corps and the cavalry; that from Thomar, by Ourem, to Coimbra, with the sixth corps; and, by his bridges over the Zezere, opened a line of operations towards the Spanish frontier, either through Castello Branco, or by the Estrada Nova and Belmonte. Preserving the power of offensive operations, by crossing the Tagus on his left, or of turning the Monte Junta by his right, he necessarily paralized a great part of the allied force, and appeared, even in retreating, to take the offensive.