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.
Lorraine Campaign is a term used by U.S. Army historians to describe operations of the U.S. Third Army in Lorraine during World War II from September 1 through December 18, 1944.
 Official U.S. Army campaign names for this period and location are "Northern France" and "Rhineland".
 The term was popularized by the publication of a volume of the same name by the U.S. Army in 1950.
 As written by the volume's author:
The South German Offensive is the general name of one of the final offensives of World War II in Europe.
 The offensive was led by the Seventh and Third armies of the United States along with the First Army of France.
 Soviet troops linked up with American forces in Czechoslovakia notably in the Battle of Slivice.
 The offensive was made by the US 6th Army Group to protect the US 12th Army Group's right flank and to prevent a German last stand in the Alps.
 However German resistance was much more fierce than in the north, which slowed the 6th Army Group's progress.
 However, by the end of April, many German divisions surrendered without a fight to the advancing American forces to avoid the inevitable destruction.
 The VI Corps of the Seventh Army linked up with the US Fifth Army, which fought through Italy, in the Alps as the Third Army advanced into Austria and Czechoslovakia, where it linked up with Soviet forces advancing from the east.
 Fighting continued a few days after the Surrender of Germany on 8 May, due to German forces fighting west to surrender to the Americans instead of the Soviets.
The Bernhardt Line (or Reinhard Line) was a German 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 U.S. Fifth Army to fight their way to the next line of defences, the Gustav Line.
 The line was defended by XIV Panzer Corps ("XIV Panzerkorps"), part of the German Tenth Army ("10.
 Armee").
General Courtney Hicks Hodges (January 5, 1887 – January 16, 1966) was a decorated senior officer of the United States Army, most prominent for his role in World War II, in which he commanded the U.S. Third Army in the Western Europe Campaign.
 In his career Hodges was a notable "mustang" officer, rising from private to general.
The M48 Patton is a main battle tank (MBT) that was designed in the United States.
 It was the third tank to be officially named after General George S. Patton, commander of the U.S. Third Army during World War II and one of the earliest American advocates for the use of tanks in battle.
 It was a further development of the M47 Patton tank.
 The M48 Patton was in U.S. service until replaced by the M60 and served as the U.S. Army and Marine Corps's primary battle tank in South Vietnam during the Vietnam War.
 It was widely used by U.S. Cold War allies, especially other NATO countries.
Major General Ernest Joseph "Mike" Dawley (February 17, 1886 – December 10, 1973) was a senior officer of the United States Army, best known during World War II for commanding the U.S. VI Corps during Operation "Avalanche" (the landings at Salerno).
 After the landings, he was relieved of his command by Lieutenant General Mark Clark, commander of the U.S. Fifth Army, and returned to the United States.
The 6th South African Armoured Division was the second armoured division of the South African Army and was formed during World War II.
 Established in early 1943, it was based on a nucleus of men from the former 1st South African Infantry Division who had returned to South Africa after the Second Battle of El Alamein in late 1942.
 The division was initially transferred to Egypt for training, after which it served in the Allied campaign in Italy during 1944 and 1945.
 In Italy, the division was initially deployed as part of the British Eighth Army, under command of Lieutenant-General Oliver Leese, and was then transferred to the U.S. Fifth Army, under Lieutenant General Mark W. Clark, for the remainder of the Italian Campaign.
 The division operated as a strongly reinforced division and was frequently used to spearhead the advance of the Corps and Army to which it was attached.
 They returned home after the end of the war in Italy and were disbanded in 1946.
 The division was also briefly active after the war from 1 July 1948 to 1 November 1949.
General George Smith Patton Jr. (November 11, 1885 – December 21, 1945) was a senior officer of the United States Army who commanded the U.S. Seventh Army in the Mediterranean and European theaters of World War II, but is best known for his leadership of the U.S. Third Army in France and Germany following the Allied invasion of Normandy in June 1944.
The X Corps was a corps-size formation of the British Army that served in the First World War on the Western Front before being disbanded in 1919.
 The corps was later re-formed in 1942 during the Second World War and saw service in the North African Campaign, later serving in the Italian Campaign where it came under command of both the U.S. Fifth Army and the British Eighth Army.

Question: What year was the the U.S. Third Army undertaking the Lorraine Campaign during World War II while the U.S. Fifth Army was engaged in Operation Diadem?
Answer: 1944