The battle of Ancona (17-18 July 1944) was the only fully independent battle fought by General Anders’ 2nd Polish Corps in Italy, and saw them capture the key port of Ancona on the Adriatic Coast.
Early in the summer of 1944 the Poles had taken part in the Eighth Army movement to the Cassino Front, and had played a famous role in the fourth battle of Cassino, finally capturing the ruins of the Monastery of Monte Cassino on 18 May. The British left the 1st Canadian and 8th Indian Divisions on the Adriatic coast (5th Corps).
On the German side the Adriatic was defended by Korpsgruppe Hauck, which formed the left flank on the 10th Army. This corps began to retreat on 7 June, with the Canadians and Indians in pursuit. The Germans received reinforcements from the 278th Infantry Division as they pulled back.
On 17 June the 5th Corps was replaced by the 2nd Polish Corps. General Anders had two Polish divisions - the 3rd Carpathian and 5th Kresowa Divisions, the brigade sized Italian Corps of Liberation and the 2nd Armoured Brigade.
The advance continued. By 20 June the Poles had reached the Aso River, sixty miles up the coast from the Adriatic battlefields of 1943 on the Moro, and well past Pescara, the target of those earlier offensives. In late June they pushed past Porto Civitanova, the eastern end of the Trasimeno Line, 15 miles to the north of the Aso. The Polish advance was finally halted ten miles to the south of Ancona, at the eastern end of the Arrezo Line. This followed the line of the Musone River, which followed a curving course to flow into the Adriatic to the south of Ancona. However past Ancona the coast turns to the north-west, and there was only a narrow gap between the middle reaches of the Musone River and the next valley, of the Esino.
The offensive was resumed on 17 July. Anders hoped to draw German attention to Carpathian Division on the coastal route, and then make his main attack with the Kresowa Division on the inland route. This division was to attack from Osimo, on the ridge north of the Musone, north-west towards Agugliano, then turn north to reach the coastal highway to the west of Ancona. The Italian Corps was to protect the left flank of the attack. The division had four infantry battalions and around 240 tanks. It faced three infantry battalions from the German 278th Division and part of the badly damaged 71st Division.
The attack was supported by 300 artillery guns and the Desert Air Force. The offensive began at dawn on 17 July, and by the end of the day the Poles had advanced four miles. On 18 July they were able to cross the Esino River (which flows north/ north-east into the Adriatic to the west of Ancona), ten miles to the north-west of Osimo, from where they could encircle Ancona. On the afternoon of 18 July the Carpathian Division entered Ancona from the south, without facing any serious resistance. The advance continued for another week, pushing the Germans out of artillery range. The advance had been so rapid that 2,500 Germans were captured in Ancona.
The surprise attack meant that the Germans had been unable to do much damage to the port of Ancona, and on 23 July the first British supply convoy entered the port. The capture of Ancona meant that the Eighth Army on the Adriatic was no longer reliant on the port of Bari, 260 miles to the south.
The Poles continue to advance north-west up the coast, taking Senigallia, 16 miles to the north-west of Ancona. However the Germans were now moving reinforcements to the Adriatic, including the 71st Infantry and 1st Parachute Division. The Poles reached the Metauro River on 22 August, another thirteen miles to the north-west, but then had to pause in front of the defences of the Arno and Gothic Line.