The only part of the Somme battlefield which is of interest in a history of the Fourth Battalion is the neighbourhood of the village of Thiepval and the wood of the same name. From Albert the River Ancre flows in a northerly direction to about St. Pierre Divion, where it turns nearly east towards Miraumont. Its banks rise steeply on both sides; its width is considerable; and the extensive marshes and shallow lagoons, which fringe so much of its course, render it a formidable obstacle. It is surprising that the enemy ever allowed the French to establish themselves on the eastern bank in 1914. By the summer of 1916, many military bridges had been built across the river and its marshes; but the allied bridge-head, though wide, was shallow, particularly at the northern end. Everywhere it was dominated by the Germans, who occupied all the commanding positions on the line of hills. To the north they held the village of Beaumont Hamel, from which they could overlook the whole course of the river, as far south as Albert. Their line crossed the Ancre near St. Pierre Divion and then ran approximately south, including the village of Thiepval, to La Boiselle. Few stronger defensive systems, than that around Thiepval, have ever been constructed on the western front. To the north the village was defended by the mighty Schwaben Redoubt, to the south by the equally formidable Leipsig Redoubt and that network of fortifications, well-styled the “Wonderwork.” Everywhere the line was well supplied with deep dugouts, which were comparatively easy to construct in the chalky soil of the district. The Germans thus had many advantages over the British. Their commanding positions gave them better opportunities for observation, and their machine guns could sweep every inch of ground in No Man’s Land. The shallowness of the bridge-head cramped the British, and hampered their assembly for the attack, while it gave unrivalled opportunities to the enemy artillery. Nevertheless, it was with the highest hopes that the allied armies looked forward to “Z” day. Months of preparation had been necessary for this offensive, and some account has already been given of the “spade work” done by the Battalion in that connection. Towards the end of June, much time was spent in reconnaissance. Before the battle began all the officers, and most of the N.C.O’s in the Battalion, knew every dump, aid post, ammunition store and source of water supply between the Ancre and Authuille Wood.