Operation Diadem

Last updated
Operation Diadem
Part of the Winter Line and the battle for Rome of the Italian Campaign, World War II
BattleforRome1944DiademPlan.svg
Allied plan for Operation Diadem
Date11 May to 4 June 1944
Location
Result Allied Victory
Belligerents

Flag of the United Kingdom.svg  United Kingdom

Flag of the United States (1912-1959).svg  United States
Flag of France.svg  France
Flag of Poland (1928-1980).svg Poland
Canadian Red Ensign (1921-1957).svg Canada

Flag of Germany (1935-1945).svg  Germany

Commanders and leaders
Flag of the United Kingdom.svg Sidney Kirkman
Flag of the United States (1912-1959).svg Geoffrey Keyes
Flag of Poland (1928-1980).svg Władysław Anders
Flag of France.svg Alphonse Juin
Flag of Germany (1935-1945).svg F. v. Senger und Etterlin
Flag of Germany (1935-1945).svg Valentin Feurstein
Flag of Germany (1935-1945).svg Traugott Herr
Flag of Germany (1935-1945).svg Eberhard von Mackensen
Units involved
Flag of the United Kingdom.svg XIII Corps
Flag of the United States (1912-1959).svg II Corps
Flag of Poland.svg II Corps
Flag of France.svg CEFI
Flag of Germany (1935-1945).svg XIV Panzer Corps
Flag of Germany (1935-1945).svg LI Mountain Corps
Flag of Germany (1935-1945).svg LXXVI Panzer Corps (elements)

Operation Diadem, also referred to as the Fourth Battle of Monte Cassino or, in Canada, the Battle of the Liri Valley, was an offensive operation undertaken by the Allies of World War II (U.S. Fifth Army and British Eighth Army) in May 1944, as part of the Italian Campaign of World War II. Diadem was supported by air attacks called Operation Strangle. The opposing force was the German 10th Army.

Contents

The object of Diadem was to break the German defenses on the Gustav Line (the western half of the Winter Line) and open up the Liri Valley, the main route to Rome. General Sir Harold Alexander, Commander-in-Chief of the Allied Armies in Italy, planned Diadem to coordinate roughly with the invasion of Normandy, so that German forces would be tied down in Italy, and could not be redeployed to France.

Four corps were employed in the attack. From right to left these were the Polish II Corps and the British XIII Corps, of the Eighth Army, and the French Corps (including Moroccan Goumiers ) and the U.S. II Corps, of the Fifth Army. The Fifth Army also controlled the U.S. VI Corps in the Anzio beachhead, some 60 miles northwest.

Diadem was launched at 23:00 on 11 May 1944 by elements of the British 4th Infantry Division and 8th Indian Infantry Division, with supporting fire from the 1st Canadian Armoured Brigade. They made a successful strongly opposed night crossing of the Garigliano and Rapido rivers. This broke into the heart of the German defenses in the Liri valley against strong opposition and drew in German theater reserves, reducing pressure on the Anzio beachhead. The French Corps pushed through the mountains to the left on 14 May, supported by U.S. II Corps along the coast. On 17 May, Polish II Corps on the right attacked Monte Cassino.

When their position collapsed, the Germans fell back from the Gustav Line to the Hitler Line some 10 miles to their rear.

On 23 May, the four corps attacked the Hitler Line. On the same day, the U.S. VI Corps attacked out of the Anzio beachhead.

The Hitler Line was breached by the 1st Canadian Infantry Division's 4th Princess Louise Dragoon Guards at Pontecorvo on 23 May. The German Tenth Army was forced to retire northwestward. The U.S. VI Corps, moving northeast from Anzio, was at the point of cutting off the German line of retreat when Lieutenant General Mark W. Clark, commander of the Fifth Army, inexplicably ordered them to turn northwest and advance on Rome instead. There is much speculation that he did this so that his Fifth Army would capture Rome ahead of the Eighth Army advancing up the Liri Valley. The German Tenth Army thus avoided being surrounded.

The Germans fought a series of delaying actions, retired to the Trasimene Line, and then to the Gothic Line (identified on German maps as the "Green" Line), north of the Arno River.

Gustav line

In his autobiography, General Mark W. Clark describes how the French Expeditionary Corps (FEC) broke through the Gustav Line in May 1944.

Meantime, the French forces had crossed the Garigliano (River) and moved forward into the mountainous terrain lying south of the Liri River. It was not easy. As always, the German veterans reacted strongly and there was bitter fighting. The French surprised the enemy and quickly seized key terrain including Mounts Faito Cerasola and high ground near Castelforte. The 1st Motorized Division helped the 2nd Moroccan Infantry Division take key Mount Girofano and then advanced rapidly north to S. Apollinare and S. Ambrogio In spite of the stiffening enemy resistance, the 2nd Moroccan Division penetrated the Gustav Line in less than two days' fighting. The next 48 hours on the French front were decisive. The knife-wielding Goumiers swarmed over the hills, particularly at night, and General Juin's entire force showed an aggressiveness hour after hour that the Germans could not withstand. Cerasola, San Giogrio, Mt. D'Oro, Ausonia and Esperia were seized in one of the most brilliant and daring advances of the war in Italy, and by May 16 the French Expeditionary Corps had thrust forward some ten miles on their left flank to Mount Revole, with the remainder of their front slanting back somewhat to keep contact with the British 8th Army. For this performance, which was to be a key to the success of the entire drive on Rome, I shall always be a grateful admirer of General Juin and his magnificent FEC... The 8th Army's delay made Juin's task more difficult because he was moving forward so rapidly that his right flank---adjacent to the British---constantly was exposed to counter-attacks. [1]

Moroccan Goumier sharpening his bayonet. Italy 1944. Goumier001.jpg
Moroccan Goumier sharpening his bayonet. Italy 1944.

In a letter to future Marshal Juin, General Mark Clark paid tribute to the Tirailleur units and Goumiers of the CEF in particular:

For me, it has been a deep source of satisfaction to see how the vital part played by the French troops of the Fifth Army throughout our Italian campaign against the common enemy has been universally acknowledged. During these long months, I have had the real privilege of seeing for myself the evidence of the outstanding calibre of the French soldiers, heirs of the noblest traditions of the French Army. Nevertheless, not satisfied with this, you and all your people have added a new epic chapter to the history of France; you have gladdened the hearts of your compatriots, giving them comfort and hope as they languish under the heavy and humiliating yoke of a hated invader. . . . With my deepest gratitude for the tremendous contribution that you have made to our joint victories, my dear General. [2]

See also

Related Research Articles

<span class="mw-page-title-main">Battle of Monte Cassino</span> Battle of World War II

The Battle of Monte Cassino, also known as the Battle for Rome, was a series of four military assaults by the Allies against German forces in Italy during the Italian Campaign of World War II. The objective was to break through the Winter Line and facilitate an advance towards Rome.

<span class="mw-page-title-main">Battle of Anzio</span> 1944 battle in Italy

The Battle of Anzio was a battle of the Italian Campaign of World War II that took place from January 22, 1944 to June 4, 1944. The operation was opposed by German and by Italian Repubblica Sociale Italiana (RSI) forces in the area of Anzio and Nettuno.

<span class="mw-page-title-main">Bernhardt Line</span>

The Bernhardt Line, or Reinhard Line, was a German Army defensive line in Italy during the Italian Campaign of World War II. Having reached the Bernhardt Line at the start of December 1943, it took until mid-January 1944 for the US Fifth Army to fight its way to the next line of defences, the Gustav Line. The Bernhardt Line was defended by XIV Panzer Corps, part of the German Tenth Army.

<span class="mw-page-title-main">Winter Line</span> Series of German military fortifications in Italy

The Winter Line was a series of German and Italian military fortifications in Italy, constructed during World War II by Organisation Todt and commanded by Albert Kesselring. The series of three lines was designed to defend a western section of Italy, focused around the town of Monte Cassino, through which ran the important Highway 6 which led uninterrupted to Rome. The primary Gustav Line ran across Italy from just north of where the Garigliano River flows into the Tyrrhenian Sea in the west, through the Apennine Mountains to the mouth of the Sangro River on the Adriatic coast in the east. The two subsidiary lines, the Bernhardt Line and the Hitler Line, ran much shorter distances from the Tyrrehnian Sea to just northeast of Cassino where they would merge into the Gustav Line. Relative to the Gustav Line, the Hitler Line stood to the northwest and the Bernhardt Line to the southeast of the primary defenses.

The Battle of Cisterna took place during World War II, on 30 January–2 February 1944, near Cisterna, Italy, as part of the Battle of Anzio, part of the Italian Campaign. The battle was a clear German victory which also had repercussions on the employment of U.S. Army Rangers that went beyond the immediate tactical and strategic results of the battle.

<span class="mw-page-title-main">Operation Avalanche</span> 1943 Allied landings in Italy

Operation Avalanche was the codename for the Allied landings near the port of Salerno, executed on 9 September 1943, part of the Allied invasion of Italy during World War II. The Italians withdrew from the war the day before the invasion, but the Allies landed in an area defended by German troops. Planned under the name Top Hat, it was supported by the deception plan Operation Boardman.

<span class="mw-page-title-main">2nd New Zealand Division</span> WW2 New Zealand Army formation

The 2nd New Zealand Division, initially the New Zealand Division, was an infantry division of the New Zealand Military Forces during the Second World War. The division was commanded for most of its existence by Lieutenant-General Bernard C. Freyberg. It fought in Greece, Crete, the Western Desert and Italy. In the Western Desert Campaign, the division played a prominent role in the defeat of German and Italian forces in the Second Battle of El Alamein and the British Eighth Army's advance to Tunisia.

<span class="mw-page-title-main">Italian campaign (World War II)</span> 1943–1945 military campaign of World War II

The Italian campaign of World War II, also called the Liberation of Italy following the German occupation in September 1943, consisted of Allied and Axis operations in and around Italy, from 1943 to 1945. The joint Allied Forces Headquarters (AFHQ) was operationally responsible for all Allied land forces in the Mediterranean theatre and it planned and led the invasion of Sicily in July 1943, followed in September by the invasion of the Italian mainland and the campaign in Italy until the surrender of the German Armed Forces in Italy in May 1945.

<span class="mw-page-title-main">VI Corps (United States)</span> Military unit

The VI Corps was activated as VI Army Corps in August 1918 at Neufchâteau, France, serving in the Lorraine Campaign. Constituted in the Organized Reserves in 1921, it was allotted to the Regular Army in 1933 and activated on 1 August 1940 at Fort Sheridan, Illinois. VI Corps took part in some of the most high-profile operations in World War II.

<span class="mw-page-title-main">Alphonse Juin</span> French Army general

Alphonse Pierre Juin was a senior French Army general who became Marshal of France. A graduate of the École Spéciale Militaire class of 1912, he served in Morocco in 1914 in command of native troops. Upon the outbreak of the First World War, he was sent to the Western Front in France, where he was gravely wounded in 1915. As a result of this wound, he lost the use of his right arm.

<span class="mw-page-title-main">Moroccan Goumier</span> Military unit

The Moroccan Goumiers were indigenous Moroccan soldiers who served in auxiliary units attached to the French Army of Africa, between 1908 and 1956. While nominally in the service of the Sultan of Morocco, they served under French officers, including a period as part of the Free French Forces.

<span class="mw-page-title-main">44th Infantry Division (Wehrmacht)</span> Military unit

The 44th Infantry Division was formed on 1 April 1938 in Vienna, about two weeks after the Anschluss of Austria. It first saw combat at the start of the war in the Invasion of Poland, and also took part in the Battle of France in 1940. After a 9-month period of coastal defence the division was transferred East. On 22 June 1941, the division took part in the invasion of the Soviet Union, attached to Army Group South. It remained in the east after the failure of "Operation Barbarossa", taking part in defensive actions for the winter against the Soviet Army offensives near Izum and Kharkov. Refurbished, the division participated in the German summer offensive, and was subsequently destroyed with the 6th Army at Stalingrad in January 1943.

<span class="mw-page-title-main">Battle of San Pietro Infine</span> WWII major engagement from 8–17 December 1943, in the Italian Campaign

The Battle of San Pietro Infine was a major engagement from 8–17 December 1943, in the Italian Campaign of World War II involving Allied forces attacking from the south against heavily fortified positions of the German "Winter Line" in and around the town of San Pietro Infine, just south of Monte Cassino about halfway between Naples and Rome.

<span class="mw-page-title-main">Trasimene Line</span> German defensive line in Italy during World War II

The Trasimene Line was a German defensive line during the Italian Campaign of World War II. It was sometimes known as the Albert Line. The German Commander-in-Chief (C-in-C), Generalfeldmarschall Albert Kesselring, used the line to delay the Allied northward advance in Italy in mid June 1944 to buy time to withdraw troops to the Gothic Line and finalise the preparation of its defenses.

<span class="mw-page-title-main">French Expeditionary Corps (1943–44)</span> French Expeditionary Corps during WWII

The French Expeditionary Corps, also known as the French Expeditionary Corps in Italy, was an expeditionary force of the French Liberation Army. Created in 1943, the corps fought in the Italian Campaign of World War II, under the command of General Alphonse Juin. Consisting of 112,000 men divided into four divisions, all but one of the divisions were colonial units, mostly Moroccans and Algerians drawn from the Army of Africa and led by French officers. Overall the Expeditionary Corps was composed of approximately 60 % of colonial troops.

<span class="mw-page-title-main">United States Army North</span> Theater Army of the U.S. Army

The United States Army North (ARNORTH) is a formation of the United States Army. An Army Service Component Command (ASCC) subordinate to United States Northern Command (NORTHCOM), ARNORTH is the joint force land component of NORTHCOM. ARNORTH is responsible for homeland defense and defense support of civil authorities. ARNORTH is headquartered at Fort Sam Houston, Texas. Redesignated ARNORTH in 2004, it was first activated in early January 1943 as the United States Fifth Army, under the command of Lieutenant General Mark W. Clark.

<span class="mw-page-title-main">XIII Corps (United Kingdom)</span> Corps-sized formation of the British Army during the First and Second World Wars

13th Corps was a corps-sized formation of the British Army that fought on the Western Front during the First World War and was reformed for service during the Second World War, serving in the Mediterranean and Middle East throughout its service.

Major-General Sir (William) Ronald (Campbell) Penney KBE CB DSO MC was a British Army officer who fought in both the First and the Second World Wars. His most notable role occurred during the latter, when he was General Officer Commanding (GOC) of the 1st Infantry Division during the Battle of Anzio, part of the Italian Campaign, in 1944.

<span class="mw-page-title-main">Battle of Rapido River</span>

The Battle of Rapido River was fought from 20 to 22 January 1944 during one of the Allies' many attempts to breach the Winter Line during the Italian Campaign of World War II. Despite its name, the battle occurred on the Gari River.

The I Fallschirmkorps was one of the main German Luftwaffe Corps during World War II.

References

  1. W. Clark, Mark (1950). Calculated Risk. Harper & Brothers. p. 348.
  2. "General Mark W. Clark". Monte Cassino Belvédère. Retrieved 29 March 2021.