The battle of the Arezzo Line (3-18 July 1944) saw the Germans fight a delaying action along a line that protected the ports of Livorno and Ancona, winning them precious time to improve the fortifications of the Gothic Line.
In the aftermath of the Allied breakthrough at Cassino and the fall of Rome on 4 June, the Germans were in full retreat back towards the Gothic Line in the northern Apennines. Marshal Kesselring attempted to set up a series of defensive positions, in the hope that these would delay the Allies long enough for the defences of the Gothic Line to be completed. The first of these, the Dora Line, was brushed aside in mid June, but the Germans had more time to work on the Tresimeno or Frieda Line. The Germans made a determined attempt to hold the Frieda line for as long as possible, but it had been too costly, and only gained them two weeks. As a result Kesselring decided to use the next series of lines for delaying actions only, holding each line for long enough for the bulk of his men to reach the next line back. The Germans would then make a stand on the Gothic Line in the northern Apennines.
The next line was the Arezzo Line, which cut across Italy to the south of the key ports of Livorno and Ancona and the communications centre of Arezzo, not far to the south-east of Florence. This line fell into three largely separate sectors.
The eastern part of the line, on the Adriatic, was along the Musone River, 12 miles south of Ancona, where it would be attacked by the advancing Polish 2nd Corps.
The central section of the line, facing the part of the Eighth Army operating west of the Apennines, was held by the 15th Panzer Grenadier Division, 334th Infantry Division, 1st Parachute Division and the Hermann Goering Division, formed into the 76th Panzer Corps. These troops defended a series of heights that ran west from Monte Castiglione Maggiore to Castello di Brolio, twenty miles west of Arezzo, running around the edge of the valley of the Chiani River. This flows south from a point south-west of Arezzo, runs the west of Lake Trasimeno, and into the Tiber. The Germans thus had yet another strong defensive position in high ground.
In the west the line began at Rosignano Solvay, 12 miles to the south of Livorno, and cut across a series of valleys that ran north-south parallel to the coast, forcing the American Fifth Army into equally difficult advances along ridge lines.
On the left flank the main American target was the port of Livorno (then generally known by its English name of Leghorn). General Crittenberger, commander of the 4th Corps, which had the task of capturing the port, decided to try and outflank the defenders. The attack would be carried out by a reinforced 34th Infantry Division (Ryder), which was given the 442nd Regimental Combat Team, 804th Tank Destroyer Battalion and the 363rd Regimental Combat Team from the 91st Division. The 363rd RCT had the task of outflanking Livorno to the east, while the main force attacked from the south. Crittenberger hoped that the threat to their lines of communication would force the Germans to retreat from the port, avoiding the sort of last ditch battle that might have done major damage to the port facilities.
The American attack took them into an area of ridges, running north-south parallel to the coast. The German defensive line started at Rosignano Solvay on the coast, and cut across a series of ridges, using the hilltop town of Rosignano Marittimo as a strong point (and also a viewpoint overlooking the US advance). The line then cut across a sizable valley to the village of Castellino Marittimo, five miles to the east. The line was defended by the 19th Luftwaffe and 26th Panzer Divisions, part of General von Senger’s 14th Panzer Corps.
The main American advance came up Highway 206, which ran up the first valley inland from the coast. The 135th Infantry Regiment was to advance along the coastal ridge and the 168th Infantry Regiment on the inland ridge, with the 442nd Infantry attacking up the valley.
The American attack began at dawn on 3 July. By the end of the day the 135th had reached Rosignano Marittimo. An attack into the village began on the morning of 4 July, and the Americans had a foothold in the south of the place by the end of the day. The Germans defended each building, and the village wasn’t entirely in American hands until late on 7 July. The 442nd and 168th Infantry had a similar fight on their hands to the east, and needed four days to capture Castellino Marittimo.
These successes meant that the main German defensive position south of Livorno had been pierced. The Americans were now able to attack on a wider front. On the left the 135th Infantry was sent towards Livorno, while the 442nd and 168th continued north, to outflank the city from the east and advance towards Pisa on the Arno. On their right the 91st Infantry entered the line, taking back the 363rd Infantry and adding the 362nd Infantry.
Further to the right the 88th Division captured Volterra on 8 July, 14 miles to the east of Castellino Marittimo. This opened a gap in the German lines, and von Senger was forced to order a general retreat. This began on the night of 12 July, just after the 91st Division had started its first attack as a complete division. The US 4th Corps was able to advance along its entire front.
The key fighting was on their left. Here the 133rd Infantry Regiment was added to the attacking forces, and was able to reach the Arno by 17 July. On their left the 168th Infantry had a harder task, as their advance directly threatened the German retreat from Livorno. On 17 July they reached Fauglia, 11 miles to the east of the port, where they were hit by German artillery and a counterattack supported by seven Tiger tanks. This attack was defeated with the aid of the divisional artillery and the regiment was able to advance north-west to Colle Salvetti, half way from Fauglia to the Arno.
Livorno itself fell to the 135th and 363rd Infantry before daylight on 19 July, after the Germans evacuated their garrison on the previous night. The Germans had still had time to destroy the port. The port facilities had been destroyed, the harbour blocked with sunken ships, the quay walls destroyed and mines scattered across the harbour and the port. These caused hundreds of casualties over the next few weeks.
Despite all of the German efforts, the port was soon back in use. The first Liberty ships carrying engineering equipment arrived on 20 July, the day after the city was captured. The engineers built bridges over the sunken ships, extended the quays, and on 26 August, five weeks after the fall of the fort, the first two Liberty ships were able to dock and unload over the quays.
The British 13th Corps came up to the new defensive lines on 5-7 July. The advance stopped with the 36th Armoured Brigade of 6th Armoured Division only three miles to the south of Arezzo, but it was clear that more troops would be needed to get through the new German defensive line. When 13th Corp reached the new line it was arrayed with the 6th Armoured Division on the right, British 4th Infantry Division in the centre and the South Africa 6th Armoured Division on the left. It was soon clear that reinforcements would be needed. The fresh 4th Indian Division had already been committed to the advance in the upper Tiber, east of Arezzo, where it was posted next to the 10th Indian Division. This only left the 2nd New Zealand Division, which had been put into the reserve ready for the attack on the Gothic Line, but it was now needed at the front, and was installed between the 6th Armoured and 4th Infantry Divisions.
The Germans defended their position stubbornly on 15 July, but withdrew overnight. Early on 16 July the 26th Armoured Brigade, 6th Armoured Division, was able to move into the upper Chiana valley to the west of Arezzo and advanced towards the city and the upper Arno. By the end of the day the British and New Zealanders had crossed a stretch of the Arno twenty files miles from Florence (at the south tip of a loop in the river), and were ready to advance north towards the next German defensive position, the Arno Line. Arezzo was quickly turned into the Eighth Army’s main railhead in the northern Apennines, and was used to support the advance towards the Arno and the early attacks on the Gothic Line.
On the right flank the task of breaking the line fell to General Ander’s 2nd Polish Corps, supported by the Italian Corps of Liberation. The Poles broke through the eastern flank of the Trasimeno Line at Porto Civitanova in late June, and during the first week of July reached the new defensive line. There was then a pause while Anders prepared for a renewed offensive. One division was to threatened up the coast, while another carried out the main assault further inland. The plan worked exactly as Anders had hoped. The assault began on 17 July, and by the following day the Poles had cut across the hills between the Musone river and the Esino river, on either side of Ancona, and were able to isolate the port, which then fell to the division advancing up the coast (battle of Ancona).
By the start of August the Germans had pulled back into the Arno line. Once again the Allies would pause before assaulting the new defensive position. The Eighth Army moved back to the Adriatic to attack towards Rimini, while the Fifth Army was given the task of attacking north from Florence. The British ended up having to fight a major battle to capture Rimini, but in the west the Americans withdrew before the main Allied attack began, and withdrew to the main Gothic Line in the mountains.