World War II: Battle of Anzio

Troops hitting the beach at Anzio, 1944
Allied troops land at Anzio, January 1944. Photograph Source: Public Domain

The Battle of Anzio commenced on January 22, 1944 and concluded with the fall of Rome on June 5. Part of the Italian Theater of World War II (1939-1945), the campaign was the result of the Allies' inability to penetrate the Gustav Line following their landings at Salerno. British Prime Minister Winston Churchill sought to restart the Allied advance and proposed landing troops behind the German positions. Approved despite some resistance, the landings moved forward in January 1944.

In the resulting fighting, the Allied landing force was soon contained due to its insufficient size and cautious decisions made by its commander, Major General John P. Lucas. The next several weeks saw the Germans mount a series of attacks which threatened to overwhelm the beachhead. Holding out, the troops at Anzio were reinforced and later played a key role in the Allied breakout at Cassino and the capture of Rome.

Invading Italy

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, Churchill proposed Operation Shingle which called for landings behind the Gustav Line at Anzio (Map).

While Alexander initially considered a large operation that would land five divisions near Anzio, this was abandoned due to a lack of troops and landing craft. Lieutenant General Mark Clark, commanding the US Fifth Army, later suggested landing a reinforced division at Anzio with the goal of diverting German attention from Cassino and opening the way for a breakthrough on that front. 

Allied Plan

Initially ignored by US Chief of Staff General George Marshall, planning moved forward after Churchill appealed to President Franklin Roosevelt. The plan called for Clark's US Fifth Army to attack along the Gustav Line to draw enemy forces south while 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. The Allied leadership also felt that should the Germans be able to respond to both threats, it would pin down forces that otherwise could be employed elsewhere.

Harold Alexander
Field Marshal Harold Alexander. Public Domain

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 and expressed concern that he would be scapegoated if the campaign failed.

Armies & Commanders


  • General Harold Alexander
  • Lieutenant General Mark Clark
  • Major General John P. Lucas
  • Major General Lucian Truscott
  • 36,000 men increasing to 150,000 men


  • Field Marshal Albert Kesselring
  • Colonel General Eberhard von Mackensen
  • 20,000 men rising to 135,000 men


Despite the misgivings of the senior commanders, Operation Shingle moved forward on January 22, 1944, with Major General Ronald Penney's British 1st Infantry Division landing north of Anzio, Colonel William O. Darby's 6615th Ranger Force attacking the port, and Major General Lucian K. Truscott's 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 at a cost of 13 killed and 97 wounded.

Rather than move quickly to strike at the German rear, Lucas began strengthening his perimeter despite offers from the Italian resistance to serve as guides. 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.

German Response

Though surprised by the Allies' actions, Kesselring had made contingency plans for landings at several locations. When informed of the Allied landings, Kesselring took immediate action by dispatching recently-formed mobile reaction units to the area. Also, he received control of three additional divisions in Italy and three from elsewhere in Europe 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.

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 Division and Rangers assaulted Cisterna.

In the fighting that resulted, the attack on Cisterna was repulsed, with the Rangers taking heavy losses. The fighting saw two battalions of the elite troops effectively destroyed. Elsewhere, 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. This bulge would soon become the target of repeated German assaults (Map).

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. By February 10, the salient had been lost and a planned counterattack the next day failed when the Germans were tipped off by a radio intercept.

On February 16, the German assault 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. The last gasps of the German offensive were blocked on February 20. Frustrated with Lucas' performance, Clark replaced him with Truscott on February 22.

General Sir Harold Alexander with Major General Lucian K. Truscott Jr. in the Anzio beachhead, Italy, 4 March 1944. Public Domain

Under pressure from Berlin, Kesselring and Mackensen ordered another attack on February 29. Striking near Cisterna, this effort was repulsed by the Allies with around 2,500 German casualties. 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.

New Plans

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.

Breaking Out

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.

A Controversial Decision

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, was 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).


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.


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Your Citation
Hickman, Kennedy. "World War II: Battle of Anzio." ThoughtCo, Apr. 5, 2023, Hickman, Kennedy. (2023, April 5). World War II: Battle of Anzio. Retrieved from Hickman, Kennedy. "World War II: Battle of Anzio." ThoughtCo. (accessed June 8, 2023).