The 'Volturno-Linie' was the German most southerly prepared defence line in Italy (September/October 1943).

Otherwise known as the 'Viktor-Linie', the line extended from Termoli in the east on the coast of the Adriatic Sea, up the Biferno river to Campobasso in the Apennine mountains and then down the Volturno river to the west and the coast of the Tyrrhenian Sea. The need for such a line, or indeed series of lines, became evident to the Germans after the Allies had made their 'Avalanche' landing at Salerno on 9 September 1943.

On the Adriatic coast, which was the responsibility of General Traugott Herr’s LXXI Pankerkorps of Generaloberst Heinrich-Gottfried von Vietinghoff-Scheel’s 10^th Army, elements of Brigadier R. K. Arbuthnot’s 11^th Brigade, part of Major General V. Evelegh’s British 78^th Division, crossed the Biferno river at dawn on 3 October 1943 following the 'Devon' amphibious landing at Termoli by commandos at 02.15 on the same morning. By a time late in the morning, the two elements had joined forces, and during the night which followed Brigadier B. Howlett’s 36^th Brigade of the 78^th Division was landed at Termoli. Logistical problems had prevented the Allies building a heavy duty bridge across the Biferno river, however, and when the bulldozed fords were washed away by heavy rains that evening there was no way to get tanks across the river to support the infantry.

On hearing of the landings at Termoli, the Oberbefehlshaber 'Süd', Generalfeldmarshall Albert Kesselring, ordered the movement of Generalmajor Rudolf Sieckenius’s 16^th Panzerdivision to the Adriatic front, presenting a major threat to the unsupported Allied infantry. As news of the German armoured formation’s arrival was received on 4 October, Evelegh demanded priority in the delivery of bridging equipment from General Sir Bernard Montgomery’s British 8^th Army. As more German armour arrived, the Allied troops across the Biferno river were forced onto the defensive and, by the afternoon of 5 October, had been pushed back to within 900 yards (825 m) of Termoli. During this time a major effort was being made to erect a heavyweight Bailey bridge, and the completion of this allowed British and Canadian armour to cross the Biferno river. During that evening, Brigadier N. Russell’s 38^th Brigade of the 78^th Division reached Termoli by sea, and the German counterattack in the course of the following morning was narrowly repulsed in desperate fighting. By a time late in the morning of 6 October, the Allies were on the attack and within six hours the Germans had started to fall back to their next line of prepared defences, the 'Barbara-Linie', on the Trigno river.

On the other coast, for which General Hans-Valentin Hube’s XIV Panzerkorps of the 10^th Army was responsible, Lieutenant General Mark W. Clark’s US 5^th Army attacked across the western end of the 'Volturno-Linie' on the lower reaches of the Volturno river during the night of 12 October. Making excellent use of rearguard tactics in which skilful used was made of terrain favouring the defence, the Germans retreated to the 'Barbara-Linie', their next defensive line to the north, which the Allies had reached by 2 November.