In 1965, the 7th Marine Regiment participated in Operations Starlite and Piranha, the first major engagements for American ground troops in South Vietnam. March 1966 saw 1st Marine Division Headquarters established at Chu Lai. By June, the entire Division was in South Vietnam, its zone of operation—the southern two provinces of I Corps—Quang Tin and Quang Ngai. Between March and October 1966 to May 1967, the division conducted 44 named operations. During the 1968 Tet Offensive, the division was involved in fierce fighting with both Vietcong and North Vietnamese Army elements. It was successful in beating back enemy assaults in its operation areas, most particularly in the City of Huế. The division received its 7th Presidential Unit Citation for service from 29 March 1966 to 15 September 1967. and an 8th one for the period 16 September 1967 to 31 October 1968.