Iron Brigade and was previously called the "Black Hat" Brigade. The 3rd Brigade Combat Team, 1st Infantry Division was known as the Iron Brigade from its formation in 1917 through World War I, World War II and Vietnam, until some time in the early 2000s when, for reasons that are still unclear, the name was changed to Duke Brigade. The unit crest was an Iron Cross in a triangle, it appears that that was also changed. The 3rd Brigade of the 4th Infantry Division is also known as the Iron Brigade. Its unit crest is similar to the medals issued to veterans
Battle of the Iron Triangle and Base 82 were taken over by Regional Forces and Rangers. III Corps Headquarters worked on plans to resumethe attack to retake Rach Bap, the last outpost still remaining in PAVN hands. General Thuần also recognized the need to clean the PAVN out of the southern part of the Iron Triangle around Phu Thu, and a plan encompassing Rach Bap, Phu Thu and the Phú Hòa area west of the Iron Triangle began to take shape. But on 30 October, before the execution of the plan, President Thieu relieved General Thuan of command of III Corps and replaced him with