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