Although the Lanz covered the left of the allies and the right of the French, the heights occupied by both were prolonged beyond that river; the continuation of the allies’ range sweeping forward so as to look into the rear of Sauroren, while the continuation of the French range fell back in a direction nearly parallel to this forward inclination of the allies’ ridge. On each side they were steep and high, yet lower and less rugged than the heights on which the armies stood opposed; for on the latter, rocks piled on rocks stood out like castles, so difficult to approach and so dangerous to assail that the hardened veterans of the Peninsula only would have dared the trial: both sides were therefore strong in defence. But Soult was forced to attack or retreat, and therefore Wellington looked anxiously for his sixth division, then coming from Marcalain by a road which run behind his ridge beyond the Lanz and fell into that valley at Oricain, one mile in rear of Cole’s left. It had been turned into that road from the higher part of the Lanz valley by Lord Fitzroy Somerset, and was followed by General Hill when he arrived at the point of divarication; the way was thus open for D’Erlon to join Soult, and the rapidity with which that marshal had seized Sauroren would thus have proved a master-stroke, if his lieutenant had pursued Hill vigorously: for the change of direction gave the sixth division a march of eighteen instead of four hours to join the army; and Hill, forced to take a position at Marcalain, covering the great road of Irurzun on Wellington’s left, was there joined by the seventh division and the whole were thrown out of the line of battle. During these important movements, which were not completed until the evening of the 28th, and which finally placed all the allies in military communication, D’Erlon remained inactive in the Bastan!