In late 1943 , the 15th Army Group under General Sir Harold Alexander was fighting their way northward in Italy against determined German opposition commanded by Generalfeldmarschall Albert Kesselring , whose forces had prepared a succession of defensive lines . East of the Apennine Mountain spine was the British Eighth Army , under General Bernard Montgomery . In October , Eighth Army had crossed the Bifurno river and pushed the German defenders from the Volturno @-@ Viktor Line defences . Delayed by logistical problems , they was not able to attack the next line of defences ( the Barbara Line ) behind the Trigno river until 2 November . However , by 9 November forward elements of the Eighth Army was in contact with the forward defences of the German Winter Line , which had been set on the high ground north of the Sangro River .