The IV Corps replaced the VI Corps in the Fifth United States Army's order of battle in Italy after Allied forces liberated Rome in the summer of 1944 when VI Corps was withdrawn to take part in Operation Dragoon, the Allied invasion of southern France. Initially the Corps had two divisions, U.S. 1st Armored and 6th South African Armoured but was reinforced with 1st Brazilian Division in November 1944, U.S. 10th Mountain Division in February 1945 and U.S. 85th Infantry Division in April 1945.

It took part in the fighting through the summer of 1944 as the 5th Army and the British 8th Army advanced north to the River Arno. In the autumn and winter of 1944 IV Corps formed the left wing of the 5th Army, taking a relative minor role in the 5th Army's assault on the Gothic Line in the central Apennine Mountains and attempt to break through to the Lombardy plains beyond.

In the spring of 1945 the Corps, still the 5th Army's left side, took part in the successful Italian spring offensive breaking out of the Apennines to outflank the units of the German Tenth and Fourteenth Armies defending Bologna forming a pincer with 8th Army on the right to surround them, and then driving on to the River Po and finally Verona and Brescia.

Campaign Credits and Inactivation

References

Center for Military History: Po Valley Campaign 1945