Battle of Anzio - Conflict & Dates:
The Battle of Anzio began on January 22, 1944 and concluded with the fall of Rome on June 5. The campaign was part of the Italian Theater of World War II.
Armies & Commanders:
- Field Marshal Albert Kesselring
- Colonel General Eberhard von Mackensen
- 20,000 men rising to 135,000 men
Battle of Anzio - Background:
Following the Allied invasion of Italy in September 1943, American and British forces drove up the peninsula until being halted at the Gustav (Winter) Line in front of Cassino. Unable to penetrate Field Marshal Albert Kesselring's defenses, British General Harold Alexander, commander of Allied forces in Italy, began assessing his options. In an effort to break the stalemate, British Prime Minister Winston Churchill proposed Operation Shingle which called for landings behind the Gustav Line at Anzio (Map).
Initially ignored by US Chief of Staff General George Marshall, planning moved forward after Churchill appealed to President Franklin Roosevelt. The plan called for Lieutenant General Mark Clark's US Fifth Army to attack along the Gustav Line to draw enemy forces south while Major General John P. Lucas' VI Corps landed at Anzio and drove northeast into the Alban Hills to threaten the German rear. It was thought that if the Germans responded to the landings it would sufficiently weaken the Gustav Line to permit a breakthrough. If they did not respond, the Shingle troops would be in place to directly threaten Rome.
As preparations moved forward, Alexander desired Lucas to land and quickly begin offensive operations into the Alban Hills. Clark's final orders to Lucas did not reflect this urgency and gave him flexibility regarding the timing of the advance. This may have been caused by Clark's lack of faith in the plan which he believed required at least two corps or a full army. Lucas shared this uncertainty and believed that he was going ashore with insufficient forces. In the days before landings, Lucas compared the operation to the disastrous Gallipoli campaign of World War I which had also been devised by Churchill.
Battle of Anzio - Landing:
Despite the misgivings of the senior commanders, Operation Shingle moved forward on January 22, 1944, with the British 1st Infantry Division landing north of Anzio, the 6615th Ranger Force attacking the port, and the US 3rd Infantry Division landing south of the town. Coming ashore, Allied forces initially met little resistance and began moving inland. By midnight, 36,000 men had landed and secured a beachhead 2-3 miles deep. Rather than move quickly to strike at the German rear, Lucas began strengthening his perimeter. This inaction irritated Churchill and Alexander as it undercut the value of the operation.
Facing a superior enemy force, Lucas' caution was justified to a degree, however most agree that he should have attempted drive further inland. Informed of the Allied landings, Kesselring took immediate action by dispatching mobile reaction units to the area. In addition, he received the equivalent of six additional divisions from OKW (German High Command). Though he initially did not believe the landings could be contained, Lucas' inaction changed his mind and by January 24, he had 40,000 men in prepared defensive positions opposite the Allied lines.
Battle of Anzio - Battling for the Beachhead:
The next day, Colonel General Eberhard von Mackensen was given command of the German defenses. Across the lines, Lucas was reinforced by the US 45th Infantry Division and US 1st Armored Division. On January 30, he launched a two-prong attack with the British attacking up the Via Anziate towards Campoleone while the US 3rd Infantry and Rangers assaulted Cisterna. In the fighting that resulted, the attack on Cisterna was repulsed, with the Rangers taking heavy losses, while the British gained ground up the Via Anziate but failed to take the town. As a result, an exposed salient was created in the lines (Map).
Battle of Anzio - A Command Change:
By early February Mackensen's force totaled over 100,000 men facing Lucas' 76,400. On February 3, the Germans attacked the Allied lines with a focus on the Via Anziate salient. In several days of heavy fighting, they succeeded in pushing the British back. On February 16, the attack was renewed and Allied forces on the Via Anziate front were pushed back to their prepared defenses at the Final Beachhead Line before the Germans were halted by VI Corps reserves. Frustrated with Lucas' performance, Clark replaced him with Major General Lucian Truscott on February 22.
Continuing the pressure, another German assault was conducted near Cisterna on February 29, but was repulsed by the Allies with heavy losses. With the situation at a stalemate, Truscott and Mackensen suspended offensive operations until spring. During this time, Kesselring constructed the Caesar C defensive line between the beachhead and Rome. Working with Alexander and Clark, Truscott helped plan Operation Diadem which called for a massive offensive in May. As part of this, he was instructed to devise two plans.
Battle of Anzio - Victory at Last
The first, Operation Buffalo, called for an attack to cut Route 6 at Valmontone to aid in trapping the German Tenth Army, while the other, Operation Turtle, was for an advance through Campoleone and Albano towards Rome. While Alexander selected Buffalo, Clark was adamant that US forces be the first to enter Rome and lobbied for Turtle. Though Alexander insisted on severing Route 6, he told Clark that Rome was an option if Buffalo ran into trouble. As a result, Clark instructed Truscott to be ready to execute both operations.
The offensive moved forward on May 23 with Allied troops hitting the Gustav Line and beachhead defenses. While the British pinned Mackensen's men at Via Anziate, American forces finally took Cisterna on May 25. By the end of the day, US forces were three miles from Valmontone with Buffalo proceeding according to plan and Truscott anticipating severing Route 6 the next day. That evening, Truscott was stunned to receive orders from Clark calling for him to turn his attack ninety degrees towards Rome. While the attack towards Valmontone would continue, it would be much weakened.
Clark did not inform Alexander of this change until the morning of May 26 at which point the orders could not be reversed. Exploiting the slowed American attack, Kesselring moved parts of four divisions into the Velletri Gap to stall the advance. Holding Route 6 open until May 30, they allowed seven divisions from the Tenth Army to escape north. Forced to reorient his forces, Truscott was not able to attack towards Rome until May 29. Encountering the Caesar C Line, VI Corps, now aided by II Corps, were able to exploit a gap in the German defenses. By June 2, the German line collapsed and Kesselring was ordered to retreat north of Rome. American forces led by Clark entered the city three days later (Map).
Battle of Anzio - Aftermath
The fighting during the Anzio campaign saw Allied forces sustain around 7,000 killed and 36,000 wounded/missing. German losses were around 5,000 killed, 30,500 wounded/missing, and 4,500 captured. Though the campaign ultimately proved successful, Operation Shingle has been criticized for being poorly planned and executed. While Lucas should have been more aggressive, his force was too small to achieve the objectives it was assigned. Also, Clark's change of plan during Operation Diadem allowed large parts of the German Tenth Army to escape, allowing it to continue fighting through the rest of the year. Though criticized, Churchill relentlessly defended the Anzio operation claiming that though it failed to achieve its tactical goals, it succeeded in holding German forces in Italy and preventing their redeployment to Northwest Europe on the eve of the Normandy invasion.