Sir Douglas Haig had for some time intended to undertake an offensive operation on a large scale during 1916 in conjunction with the French, and in view of the continual increase in the strength of the British Armies it was clearly desirable that the launching of the battle should be delayed as long as possible consistent with the advance of the summer. But in view of the great pressure at Verdun it was decided that the British attacks should begin at the latest at the end of June, with the objects of relieving our Allies and of pinning as many enemies as possible to the front opposite the British Armies, in addition to the tactical improvement of our positions. The part of the enemy's lines selected for attack was the right of the British front, opposite which the Germans occupied high ground forming the watershed between the River Somme and the rivers flowing north-east into Belgium. The general direction of this watershed, which consists of a chalk country of broad swelling downs and deep well-wooded valleys, is roughly from east-south-east to west-north-west. The aspect of this country bears a general resemblance to parts of Wiltshire, and the gentle undulations of the higher slopes of the hills, which descend with unexpected abruptness into waterless valleys lined with banks whose declivitous sides seem to have been shaped by human agency, cause the resemblance to be one also of detail. From this watershed a series of long spurs runs south-westerly towards the Somme, and on their lower slopes the German lines ran from Curlu near the river at first north and then almost due west to Fricourt, a distance of some 10,000 yards. At Fricourt the lines took an abrupt turn northward for a further 10,000 yards when they crossed the Ancre, a tributary of the Somme, near Hamel. From this point they continued in a generally northerly direction, passing through Beaumont Hamel, west of Serre and between Hébuterne and Gommecourt. In the neighbourhood of the two last-named villages the lines crossed the summit of the main watershed, and thence descended gently in a north-easterly direction towards Arras. On the 20,000 yards between the Somme and the Ancre the enemy had already prepared a strong second system of defence about two miles in rear of the front system; and on the whole front from Gommecourt to the Somme he had spared no effort in the nearly two years of his uninterrupted occupation to render these positions impregnable. The strengthening of woods and villages into fortresses, and the skilful use of the ground in siting trenches and gun and machine-gun emplacements, had in fact woven his successive lines of trenches into one composite system. Yet further in rear he was still at work improving existing defences and constructing new.