'Seitensprung' (i) was the German attack, by forces including Hauptmann Josef Prentl’s Flakkampfgruppe 'Prentl', within Generaloberst Eberhard von Mackensen’s 14^th Army against the 'Shingle' lodgement of Major General Lucian K. Truscott’s US VI Corps of Lieutenant General Mark W. Clark’s US 5^th Army at Anzio on the west coast of Italy (29 February/2 March 1944).

Operating on the front of Generalleutnant Dietrich von Choltitz’s LXXVI Panzerkorps, the Kampfgruppe was credited with the destruction of more than 40 Allied tanks and the defeat of several infantry assaults.

The German forces were compelled to make this last attempt to defeat the 'Shingle' lodgement largely because of the fact that Adolf Hitler attached great political and propaganda significance to its elimination. On 22 February, therefore, von Mackensen proposed another attack, on this occasion in the southern part of the lodgement, to punch through the US positions from Cisterna to Nettuno, and on a considerably wider front than in 'Sonnenaufgang', the previous effort. von Mackensen intended to use Generalmajor Paul Conrath’s Panzerdivision 'Hermann Göring', Generalmajor Smilo Freiherr von Lüttwitz’s 26^th Panzerdivision under the temporary command of Oberst Hans Hecker, and Generalleutnant Heinrich Greiner’s 362^nd Division in the first wave, and to hold Generalleutnant Walter Fries’s 29^th Panzergrenadierdivision in reserve to exploit and mop up. Preparations for an attack were to be simulated in the area of the Albano road farther to the north, where dummy tanks were to be placed, widespread raids to be made, and conspicuous vehicle movements undertaken in an effort to deceive the Allied command. Although he wished to start his attack at once in order to gain surprise and give the Allied forces little chance to recover from the previous offensive, von Mackensen was delayed by the need to regroup his formation and receive delivery of the required ammunition.

With the approval of Generalfeldmarschall Albert Kesselring, the Oberbefehlshaber 'Südwest' as well as commander of Heeresgruppe 'C', von Mackensen therefore scheduled 'Seitensprung' (i) for a start at the break of day on on 28 February, but on the day before asked for a one-day postponement as the German force was not ready as the adverse weather had prevented the tanks and self-propelled guns from moving off the roads and up forward to the line of departure. Kesselring agreed to the postponement. Very heavy rain fell on 28 February, the day before the rescheduled start, and both Kesselring and von Mackensen believed that this would in fact aid the Germans to attain tactical surprise and deny the Allied forces the benefits of tank, air and naval gunfire support.

During the afternoon of 28 February, a smoke screen along the front held by Brigadier General John W. O’Daniel’s US 3^rd Division in the Cisterna area concealed the final German troop movements. At about 24.00 the German artillery shifted the main weight of its fire from the British sector to the north, and started to lay down a heavy bombardment in the 3^rd Division’s area. Exhausted and depleted by six weeks of fighting, the 3^rd Division had developed its forward defence line into a well-integrated barrier of strongpoints. Suspecting that an attack would probably be made in the early hours of 29 February, O’Daniel, who had assumed command of the division on 17 February on Truscott’s elevation to command of the VI Corps, ordered a large volume of artillery fire to be placed on the German forces' logical avenues of approach.

In the event, the shelling failed to disrupt the German attack. On the 3^rd Division’s left, German troops overran a company of the 509^th Parachute Battalion, and only one officer and 22 men managed to fall back some 700 yards (640 m) back to the battalion’s main line of resistance. Here a reserve company of 96 men, supported by a considerable weight of artillery and mortar fire, stopped the German thrust. In the main effort, the 362^nd Division, reinforced by tanks of the 26^th Panzerdivision and Panzerdivision 'Hermann Göring' fell frontally onto the 3^rd Division. The weight of the German onslaught dented but did not break the US forward defence line. Farther to the east, Generalleutnant Hans-Georg Hildebrandt’s 715^th Division and two battalions of SS-Gruppenführer und Generalleutnant der Waffen-SS Max Simon’s 16^th SS Panzergrenadierdivision 'Reichsführer-SS' struck the 504^th Parachute Infantry, making a small breakthrough which was rapidly sealed and contained.

A German task force striking Brigadier General Robert T. Frederick’s 1^st Special Service Farce along the Mussolini Canal made no progress at all.

Heavy fighting continued throughout the day, and while thick cloud and frequent rain squalls grounded Allied warplanes during the morning, during the afternoon the weather cleared sufficiently for 247 fighter-bomber and 24 light bomber sorties to be flown in support of the ground troops by striking at German armour and infantry. Despite its heavy losses, at the end of the day the 3^rd Division launched a counterattack and retook the few hundred yards of ground it had earlier lost.

Despite the fact that his assault units had suffered high casualties in men and armour, von Mackensen continued his attack on 1 March. The German effort was noticeably weaker, however, and made no progress. During the evening of the same day, von Mackensen admitted that his formations could not eradicate the Allied lodgement, and Kesselring ordered him to bring his offensive to a halt and limit his activity to local counterattacks.

The weather was totally clear on 2 March, and Allied warplanes were able to operate in some strength: 241 Consolidated B-24 Liberator and 100 Boeing B-17 Flying Fortress heavy bombers, escorted by 113 Lockheed P-38 Lighting and 63 Republic P-47 Thunderbolt fighters, dropped a heavy bomb tonnage immediately behind the German line; medium and light bombers, together with fighter-bombers, struck at German tanks, gun positions, and troop assembly areas. This impressive display of air power came at the end of the German attack, which had cost the Germans more than 3,000 casualties (including 500 men taken prisoner), and marked the final German attempt to drive the 'Shingle' lodgement back into the sea.

Hurried preparations, confused orders, faulty communications, poor tank and artillery support, as well as a firm Allied defence, had combined to cause German failure.