CHAPTER I
THE GERMAN RETREAT UPON THE ARRAS-SOISSONS FRONT

Hindenburg's retreat—The advance of the Fifth and Fourth Armies—Capture of Bapaume and Peronne—Atrocious devastation by the Germans—Capture of guns at Selency—Definition of the Hindenburg Line—General survey.

In the latter days of 1916 and the beginning of 1917, the British Army, which had in little more than two years expanded from seven divisions to over fifty, took over an increased line. The movement began about Christmas time, and early in the New Year Rawlinson's Fourth Army, side-stepping always to the south, had covered the whole of the French position occupied during the Somme fighting, had crossed the Somme, and had established its right flank at a point near Roye. The total front was increased to 120 miles, which may seem a small proportion as compared to the whole. In making such a comparison, however, one must bear in mind the difference in the effort of sustaining an army in one's own country and in a foreign land with all communications by water. The task of the British was continually made more difficult by the precarious nature of their connection with their base. Dulness of vision may be as dangerous to a nation as treason, and no enemies could have harmed the country more than those perfectly sincere and patriotic individuals who had for so long opposed the construction of a Channel tunnel.

The general disposition of the British forces after this prolongation to the south was as follows. Plumer's Second Army still held that post of danger and of honour which centred round the Ypres salient. South of Plumer, in the Armentières district, was the First Army, now commanded by General Horne, whose long service with the Fifteenth Corps during the Somme Battle had earned him this high promotion. Allenby's Third Army carried the line onwards to the south of Arras. From the point upon which the British line had hinged during the Somme operations Gough's Fifth Army took over the front, and this joined on to Rawlinson's Fourth Army near the old French position. From the north then the order of the armies was two, one, three, five, and four.

The winter was spent by both sides in licking their wounds after the recent severe fighting and in preparing for the greater fighting to come. These preparations upon the par