Despite these additions, the Fourteenth Army outnumbered the Allies at Anzio by 4 February. But the German force was a hodgepodge of rapidly thrown together units. All were critically short of ammunition, training, qualified leaders, and reserves. Allied air attacks had disrupted communications, hampered troop and supply movements, and caused morale problems. From the outset Mackensen had doubted the available force could eliminate the Anzio beachhead, but he prepared a forceful counterattack nonetheless.
The 4th Parachute and 65th infantry Divisions of the I Parachute Corps were to pinch off the Campoleone salient and recapture the Factory at Aprilia. The same units would then break through to the sea along the Albano Road. Elsewhere the LXXVI Panzer Corps, consisting of the 3d Panzer Grenadier, 715th Motorized Infantry, 71st Infantry, Hermann Goering, and 26th Panzer Divisions would attack south of Cisterna along the Mussolini Canal and attempt to breach the Allied perimeter and advance on Nettuno and Anzio.
The counterattack opened with an artillery barrage on 3-4 February, followed by armored and infantry assaults which smashed into the partially prepared British 1st Division defenses in the Campoleone salient. The British held, despite suffering 1,400 casualties, but their dangerously exposed position prompted Lucas to order their withdrawal to one mile north of the Factory and Carroceto on the night of 4-5 February, a retreat of about 2.5 miles. Although the salient was eliminated, the Germans failed to break the Allied line or retake the Factory. The undulating and soggy Albano Road area was just as inhospitable to German armor and infantry as it had been to Allied forces the week before.
However, the critical situation the Germans created in the Allied center convinced Lucas to form a beachhead defense line running from the Moletta River in the north, through the fields of the central sector, to the Mussolini Canal in the south. He issued orders to all Allied troops that this was the final line of resistance to be held at all costs—the shallow beachhead precluded any further retreat.
The Germans renewed their attacks on 7 February in the weakened British 1st Division sector and, in two days of bitter fighting, pushed the British troops from the Factory and Carroceto. Although battered and exhausted, they managed to maintain a coherent line and were reinforced on 10 February by the 1st Armored Regiment, CCA, 1st Armored Division (itself at 50 percent strength), the 509th Parachute Infantry Battalion, the 504th Parachute Infantry Regiment, and the 179th and 157th regiments of the U.S. 45th Infantry Division. Ordered to counterattack and retake Aprilia on 11 February, the 179th Infantry and 191st Tank Battalion began a two-pronged attack seeking to outflank the Germans holding the Factory. In two days of costly, hand-to-hand fighting, the Americans failed to retake the lost ground, but inflicted heavy losses on the enemy. Lucas still expected further attacks in the weakened central sector and removed the British 1st Division from the line, replacing it with the British 56th and U.S. 45th Infantry Divisions. As an added precaution, VI Corps artillery was strengthened and Allied tactical air attacks were stepped up.
Spurred by the elimination of the Campoleone salient, the Germans continued their counterattack on 16 February by moving down the Anzio-Albano Road on a four-mile front. The brunt of the assault hit the 45th Division sectors held by the 157th and 179th Infantry regiments. The initial attacks by the 3d Panzer Grenadier and 715th Motorized Infantry Divisions were beaten back with heavy losses, allowing only minor penetrations, while the 180th Infantry rebuffed lighter attacks. Just before midnight, however, enemy persistence paid off. A gap was created between the 179th and 157th Infantry, which was promptly exploited by three German regiments supported by sixty tanks. By dawn the Germans had driven a two-by-one-mile wedge in the center of the 45th Division and were poised to break the Allied line, threatening the entire beachhead. Compounding the already critical situation, the 179th Infantry attempted to withdraw in full view of the enemy the following afternoon and suffered heavy casualties. All through 16-17 February the Allies scrambled to plug the gap with hastily redeployed 90-mm. antiaircraft guns, naval gunfire, and units of the 1st Armored Division. The XII Tactical Air Command flew 730 ground support sorties and later claimed that the total weight of bombs dropped and the number of bombers employed was the greatest ever allotted up to that date in direct support of ground forces.
The Germans launched a more intense assault against the 45th Division at dawn on 18 February and destroyed one battalion of the 179th Infantry before pushing the remainder of the unit back a half mile farther to Lucas' final defensive line by midmorning. Fearing that the 179th Infantry was in danger of giving way, Lucas ordered Col. William O. Darby to take command of the unit and allow no further retreat. The regiment held, later counting 500 dead Germans in front of its positions. Elsewhere, the 180th and 157th regiments also held their positions in spite of heavy losses during three days of German attacks. By midday, Allied air and artillery superiority had turned the tide. When the Germans launched a final afternoon assault against the 180th and 179th regiments, it was halted by air strikes and massed mortar, machine gun, artillery, and tank fire. Subsequent enemy attacks on 19 and 20 February were noticeably weaker and were broken up by the same combination of Allied arms before ground contact was made The crisis had passed, and while harassing attacks continued until 22 February, VI Corps went over to the offensive locally and succeeded in retaking some lost ground.
The Germans could ill afford the loss of the 5,389 men killed, wounded, and missing during their five-day counterattack. Enemy troop morale plummeted, and many units lost their offensive capability. The 65th Infantry Division's combat strength had dropped to 673 effectives by 23 February, and one regiment of the 715th Motorized Infantry Division numbered fewer than 185 men. Allied casualties numbered some 3,496 killed, wounded, or missing in addition to 1,637 nonbattle casualties from trench foot, exposure, and combat exhaustion. Allied commanders at Anzio often claimed that losses would have been lower if soldiers were periodically rotated away from the lines, but replacements simply were not available. All 96,401 Allied soldiers were required to hold the 35-mile perimeter against an estimated ten German divisions in the Fourteenth Army, totaling 120,000 men by 12 February.
At midnight, 28 February, German artillery signaled the commencement of the new attack. But VI Corps and 3d Division artillery responded in mass, returning twenty shells for each one fired by the Germans, expending 66,000 rounds on 29 February alone. When the enemy infantry advanced at dawn at a half-dozen points along the 3d Division front, only one attack made any progress, penetrating 800 yards northeast of Carano before being halted with heavy losses. The other attacks fared less well amid a hail of American artillery and mortar fire. Attacking on too broad a front, the Germans lacked the overwhelming strength needed to break through anywhere, and by the end of the day they had barely dented the American line. Over the next several days, the well-entrenched Americans, supported by closely coordinated artillery, armor, and air support, shattered subsequent German attacks. Even though the 7th and 15th Infantry regiments and the 509th Parachute Infantry Battalion often were hard pressed and suffered heavy losses between 1 and 4 March at the hands of the 715th and the 16th SS Panzer Grenadier Divisions, all three units held their positions and beat back successive enemy assaults. The Germans continued to seek a breakthrough, but their efforts gradually weakened. Mackensen realized that the Fourteenth Army had spent itself in a costly and futile offensive after a last German assault failed on 4 March.
The final five-day German counterattack cost 3,500 men killed, wounded, and missing, plus thirty tanks destroyed. It had failed to eliminate the beachhead, and 3d Division counterattacks quickly reclaimed all territory. From then, the Germans went over to the defensive, clearly incapable of mounting any further serious offensive action.
