Kesselring expected the Allies to invade Sicily next, and if the island was chosen as a target, the Allies could send fighters from Malta and Tunisia to support the landing operation. To this end, Kesselring reinforced Italy with 6 coastal defense divisions, 4 mobile divisions and 2 German mobile divisions , the 15th Panzergrenadier Division and the Hermann Goering Panzer Division , both of which were rebuilt after the destruction of Tunisia. Kesselring was well aware that such a force would be sufficient to withstand a small Allied landing, but not a massive invasion. So he pinned his hopes on counterattacking as soon as the Allies began to land in Sicily, so he ordered Colonel Paul Conrath, commander of the Goering Panzer Division, to attack as soon as he found any sign of an Allied invasion of the fleet, with or without the consent of the island's commander, General Alfredo Guzzoni.
Kesselring hoped that the German U-boats would crush the Allied invasion fleet, but they achieved little. On 4–5 July, U-953 sank two U.S. tank landing ships (LST), U-375 sank three British transport ships; on 10 July, U-371 sank one Liberty and one tanker; and the 2nd Air Fleet, originally stationed there and commanded by Richthofen since July, was forced to withdraw most of its aircraft to the European continent due to the allied air force.
Kesselring flew to Sicily on 12 July to inspect the island, judging that the troops could only continue to delay the Allied advance, but could not hold on for long, and sooner or later they would have to retreat. Nevertheless, Kesselring sent the 29th Panzergrenadier Division to reinforce Sicily on 15 July. On 16 July, Kesselring took an airship to Sicily and gave orders to the local senior German general, The General Hans Valentine Hoobe, a heavy anti-aircraft artillery unit, in order to hold the island. In the end, Kesselring succeeded in holding the Allies back for a month, and the Allies did not occupy Sicily until August 17.
A week before the Allies completely occupied the island (i.e. on 10 August), Kesselring had begun a retreat of troops, which was probably the most successful German operation of the battle. Despite the Allied superiority in land, sea and air, Kesselring was able to withdraw 40,000 men, 96,605 vehicles of all kinds, 94 artillery, 47 tanks, 1,100 tons of ammunition, 970 tons of fuel and 15,000 tons of reserves. Under his command, the Germans achieved near-perfect three-service coordination, which his rival Eisenhower failed to do.
With the fall of Sicily, the German high command feared that Italy would withdraw from the war, but Kesselring remained confident that Italy would continue to fight. The High Command, believing that Kesselring was too close to Lin and the Italian government, began to treat him coldly, and sent Rommel to northern Italy and Studen to Rome. The High Command ordered that Studen's 1st Airborne Army should immediately capture its capital in the event of Italy's defection. On 25 July 1943, Benito Mussolini was stripped of power, and the High Command and Rommel began planning to occupy the whole of Italy by force and disarm the Italian army, a plan that Kesselring had not yet heard of.
After consulting Rommel and Jodl, Hitler decided that without the assistance of the Italian army, the German army would not be able to hold the Italian peninsula. Kesselring was ordered to leave southern Italy and go north to integrate his Army Group C with Rommel's Army B and place it under Rommel's command. Kesselring was then scheduled to transfer to Norway. Kesselring believed that this would expose southern Germany directly to Allied bombers from Italy, whose forces would be able to break through all the way to the po valley, and was shocked that the German top brass would abandon Italy, feeling that such a abandonment was completely unnecessary. Believing that the Allies would not fight beyond their air cover (up to Salerno), Kesselring was convinced that Rome could hold out until the summer of 1944. On 14 August 1943, Kesselring submitted his resignation.
At this point, SS Gen. Carl Wolff, the supreme SS and police officer in Italy, told Hitler that Rommel was "politically unreliable" and claimed that Kesselring's presence in southern Italy was an important factor in preventing the country from defecting earlier. Taking Wolfe's opinion into account, Hitler rejected Kesselring's resignation.
On 8 September, Italy withdrew from the war. Anticipating that the Allies would launch an air and sea invasion there, Kesselring immediately moved to take control of Rome. Kesselring ordered the 3rd Panzergrenadier Division and the 1st Airborne Division to approach the city, and attempted unsuccessfully to blockade the entire Italian Army Staff in Monterotondo by surprise. Although Kesselring's 2 German divisions had to face 5 Italian divisions, of which 2 were armored, he managed to repel the Italians and capture Rome within two days.
Hitler, on the other hand, sent a large number of German troops into Italy and quickly disarmed the latter. In the area of charge of Rommel's B Army Group, Italian troops were sent to Germany for forced labor, except for those willing to join the Germans against the Allies, while in the areas under Kesselring's control, they were disarmed and left to let the Italian soldiers return home on their own. The Italian general Gonzaga was immediately shot dead by the Germans for refusing to disarm his 222nd Coastal Defense Division. Most of the 184th Rain Cloud Airborne Division joined the German side and later became the base of the 4th Airborne Division. On the Greek island of Kefalonia, 5,000 Italian soldiers of the 33rd Mountain "Acqui" Division were slaughtered by the Germans without Kesselring's orders. On 12 September, German commandos, under the command of SS Lieutenant Colonel Otto Skolzny, carried out Operation Oak, planned by Studen, to rescue Mussolini. The details of the operation were carefully arranged, deliberately not to let Kesselring know, but the latter still knew about the operation. Hitler commented that "Kesselring was too upright in the face of the natural traitors in the local area."
With the arrival of German troops, Italy was effectively an occupied country by this time. Italy's attempt to turn against the enemy was extremely contemptuous of both the Allies and the Germans, which had a considerable impact on the subsequent development of the situation.
Although Kesselring had no de facto command, he wanted to continue fighting. At the Battle of Salerno in September 1943, Kesselring and The 10th Army of General Heinrich von Wittinghof launched a full-scale counteroffensive against the Allies, inflicting heavy casualties and forcing them to retreat in several areas, with allied commanders even considering a full retreat. Due to the proximity of the German airfield, the 2nd Air Fleet dispatched 120 aircraft over Salerno on 11 September 1943, using Fritz X anti-ship missiles to hit the Allied cruisers War Hate, Uganda and Savannah, while one Liberty was sunk on the 14th and the other was damaged the next day. However, the allied sea fleet fire greatly damaged the Advancing German units on the front line, and coupled with the strong resistance of the Allied forces and the advance of the British 8th Army, the Germans were ultimately unable to drive the Allies back to the sea. On 17 September 1943, Kesselring allowed Wittinghof to order his troops to halt their attack and retreat.
Although Kesselring was repulsed in this battle, he also managed to gain valuable time. During this period, Kesselring violated the orders of his superiors and built a series of strongholds that could be held by the Germans, including the three lines of defense of Wortunow, Bayibala and Bernhardt. After a month of difficult fighting, the Allies advanced to Kesselring's main line, the Gustav Line, in November 1943. Kesselring said in his memoirs that if he had been able to obtain Rommel's "useless" troops, his defense line could have been improved.
In November 1943, Kesselring met with Hitler and assessed the optimistic situation on the Italian battlefield, saying that he could block the Allies on the winter line south of Rome, giving Hitler a shot in the arm. In addition, Kesselring further promised that he could delay the Allies to the Apennines for at least six months. Therefore, on November 6, 1943, Hitler ordered Rommel and his Army Group B headquarters to move to France to take charge of the local Atlantic barrier, preparing to resist the allied landing offensive expected in the spring of 1944. On 21 November, Kesselring regained command of all German forces in the Italian theater and assumed the title of Commander-in-Chief of the Southern Theater, along with Army Group C. Hitler later explained: "I have always accused Kesselring of being too optimistic about things ... It turned out that Rommel was wrong, and my decision not to dismiss Kesselring was the right one; I had thought of Kesselring as an untrustworthy political ideologue and a military optimist. In my opinion, a lack of optimistic military leadership is not feasible. ”
On the night of December 2, 1943, the Luftwaffe dispatched 102 Ju 88 bombers to attack The Port of Bari with remarkable success. The Germans used a large number of scattered sheets of metal to confuse the Allied radar and found that the harbor was crowded with brightly lit Allied ships, resulting in the worst Allied ship losses since Pearl Harbor. Two ammunition ships and an oil tanker were hit, and the burning of oil in the harbor caused a fire, and the ammunition also exploded. Another 16 ships were sunk by the Germans and another 8 were wounded, leaving the port unable to perform combat functions for three weeks. In addition, one of the sunken ships, the John Harvey, was attacked when a large amount of toxic mustard gas leaked out, forming a poisonous mist that covered the harbor.
The Allies attempted to break through the Gustav Line at the Battle of Cassino in January 1944, and initially succeeded: the British 10th Army broke through a section of the line of defense that was only defended by the German 94th Infantry Division, thus endangering the entire front of the German 10th Army. At the same time, Kesselring received another warning that the Allies were about to launch an amphibious attack, so he quickly mobilized the reserve 29th and 90th Panzergrenadier Divisions to the Cassino front. By dispatching these two units, the situation on the front line was eventually stabilized, but as a result the Roman garrison was reduced and the garrison was weakened. By the time the Allies landed in Anzio, Kesselring felt overwhelmed.
Although slightly caught off guard, Kesselring quickly amassed his forces, bringing in the 14th Army in northern Italy, commanded by General Eberhard von Mackensen, the 29th and 90th Panzergrenadier Divisions from the Cassino Front, and the 26th Panzer Division from the 10th Army, and the High Command transferred some divisions from other fronts in an attempt to control the situation. By February, Kesselring was finally able to launch an attack on Anzio, who had landed on the Allied forces, but his forces were not strong enough to crush the enemy's beachhead positions, and the situation was deadlocked, for which he blamed himself, the High Command, and Mackensen for several avoidable mistakes.
On the other hand, the Allies who fought hard in Cassino were finally on the verge of breaking through the Valley of Lili in February 1944. In order to defend the "Fortress of Cassino", Kesselring transferred the well-trained and well-equipped German 1st Airborne Division on 26 February. As a result, throughout March, the Allies suffered heavy casualties and huge ammunition consumption, but were still unable to break through the Gustav Line.
On May 11, 1944, the British general Harold Alexander launched "Operation Crown", which finally broke through the Gustav Line, and the German 10th Army was forced to withdraw, and there was a gap between the 10th Army and the 14th Army in the operation, and there was a danger of being surrounded by allies. As a result, Kesselring dismissed Mackensen and replaced him with General Joachim Remelson Panzer Corps. Fortunately for the Germans, Lieutenant General Mark Clark of the Us Army, because of his over-focus on the occupation of Rome and did not take into account the current superiority of the self-army, gave the 10th Army the opportunity to withdraw to the next line of defense, the Lasimian Line, to merge with the 14th Army and then carry out the evacuation operation.
For Kesselring's performance in these battles, Hitler awarded him the Knight's Cross of the Iron Cross with a Diamond Oak Leaf and Sword at the Wolf's Den Base in Rustenburg, East Prussia on 19 July 1944. The next day, there was a coup d'état in wolf's Den that attempt to assassinate Hitler, which Kesselring received from Goering that night, and then Kesselring, like many senior German generals, sent a telegram to Hitler, reaffirming his loyalty to the latter.
Throughout July and August 1944, Kesselring fought another stubborn defensive battle and gradually withdrew his troops to another main line of defense in the north of Florence, the Gothic Line. There, Kesselring completely halted the Allied offensive. Kesselring himself was wounded in the fierce fighting between September and October: on 25 October 1944, Kesselring's car was hit by a shredded shell flying from the side of the road, seriously injuring his head and face, and he did not return to command until January 1945.
Thanks to Kesselring's order to intervene, many Italian cities with a deep artistic and historical background were protected from war, including Rome, Florence, Siena and Orvieto; in some cases, the famous Italian monument, the "Ponte Vecchio", was ordered to install booby traps rather than blow them up. Other florentine bridges, also historic, were destroyed on Kesselring's orders, and with the exception of the Old Bridge, which was used to booby trap allies, buildings at both ends of the bridge were destroyed to delay the Allies' crossing of the Arno River. Kesselring also supported the decision to make Rome and Chieti undefended cities. In fact, as far as the defense of the Tiber Is concerned, the city of Rome has a high tactical value. Since these cities did not undergo "demilitarized" operations and remained centers of government and industry, the Allies did not recognize their non-defensive statements. Therefore, despite the Germans' incessant declarations of non-defense, the Allies bombed Rome more than 50 times, and Florence was also subjected to air raids. In this case, the status of the undefended city becomes meaningless.
The monastery of Monte Cassino is an excellent observation point, but kesselring did not give it military use to protect it. But because the Allies did not believe that the Germans had not used the monastery as an artillery observation point, Kesselring's efforts failed: in the early morning of February 15, 1944, 142 B-17 Air Fortress bombers, 47 B-25 Mitchell bombers and 40 B-26 medium bombers threw 1150 tons of high explosives and incendiary bombs at the monastery, reducing the historic monastery to rubble. Kesselring knew that some of the artworks transferred from Mount Cassino had ended up in the hands of Goering, who was fond of collecting artefacts, and he had also shot some of the soldiers who looted the artifacts. The Germans refused to let the Italian government take over the artworks because they feared that "the Italians would sell them all to Switzerland." A 1945 Allied survey showed that Italy's cultural treasures suffered less damage in the war. Thanks to Kesselring's personal interest in artifacts and his efforts, a large number of works of art have survived.