 After the Somme Offensive ended in November , the Allies began to prepare for a series of combined Allied offensives in April 1917 . These plans would not be significantly disrupted by the German Army 's strategic withdrawal to the " Hindenburg Line " in northern France . The phased withdrawal , conducted from February to April , reduced the German front by 25 miles ( 40 km ) . The regiment 's six second @-@ line battalions arrived on the Western Front with the 57th ( 2nd West Lancashire ) Division in February 1917 . 
