I Corps tactical zone

From Citizendium
Jump to navigation Jump to search
This article is developing and not approved.
Main Article
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
This editable Main Article is under development and subject to a disclaimer.
I Corps

During the Vietnam War, the Army of the Republic of Viet Nam (ARVN) defined I Corps tactical zone (I CTZ)[1] as the five northernmost provinces of South Vietnam: from approximate north to south, these were

Provinces in I CTZ
1965 name Capital Current name
Quang Tri Dong Ha Quang Tri
Thua Thien Hue Hue Province
Quang Nam Province Tam Ky Quang Nam Province
Quang Tri Province Dong Ha Quang Tri Province
Quang Ngai Province Quang Ngai Quang Ngai Province

Its northern border was the Demilitarized Zone (DMZ) with North Vietnam; National Highway 9 ran along it. On the west, it bordered Laos and areas of the Ho Chi Minh trail.

Corps tactical zone boundaries

The largest cities of the zone were Hue and Danang. Major engagements, at small locations, included the Battle of Khe Sanh and the Battle of Con Thien.

North Vietnamese equivalents

These areas came under Military Regions 4 and 5, as well as the B-5 Front.[2]

U.S. equivalents

American forces in I Corps began with III Marine Amphibious Force, its name changed from the usual designation of III Marine Expeditionary Force due to "expeditionary force" having unfortunate connotations, to the Vietnamese, from French usage. Later in the war, the Military Assistance Command, Vietnam, asserted more control over the Marines, variously putting a forward echelon of MACV there, and establishing TASK FORCE OREGON and Provisional Corps, Vietnam.


In 1972, Hoang Xuan Lam was dismissed for incompetence.


  1. Corps is usually a tactical, rather than geographical structure; the U.S. renamed its Vietnam War corps formation s "field forces" to avoid confusion. In July 1970, the Republic of Vietnam redesignated its CTZs as Military Regions (MR). ARVN MR numbers, however, had no relationship to the People's Army of Viet Nam's MR numbering scheme.
  2. Pearson, Willard (1975), Vietnam Studies : The War in the Northern Provinces, Office of the Chief of Military History, U.S. Army