The Philippine Constabulary, which was to be disbanded and absorbed into a civilian police force beginning in 1991, was the oldest of the nation's four armed forces. It was established by the United States colonial government in 1901 to preserve peace and order and provided the nucleus of the first regular division of the Commonwealth's army in 1936. It remained an element within the army (after 1946 as the Military Police Command) until 1950 when it was reestablished as a separate force. It was formally renamed the Philippine Constabulary in 1959.

After its renaming, the Philippine Constabulary officially constituted a national police force and essentially operated as a gendarmerie, holding primary authority for law enforcement and domestic security. It was responsible for dealing with largescale crime, conducting wide-area operations, and enforcing the peace and national laws, especially in remote areas where other forces were nonexistent or ineffective. The constabulary also played a prominent role in combating the Moro and communist insurgencies. Following the creation of the Integrated National Police in 1975, the constabulary operated with the new force under a joint command structure (see Law Enforcement , this ch.).

Organized and equipped along military lines, the constabulary was headed in 1990 by a major general, who served concurrently as the director general of the Integrated National Police. He was assisted by deputies for the Philippine Constabulary and Integrated National Police, and by his Camp Crame, Manila, headquarters staff, which was similar to the AFP's General Headquarters staff. Constabulary forces throughout the country were supported and controlled through a system of regional commands, with one command in each of the country's twelve political regions. Under the operational control of the area commands, the regional commands controlled subordinate Philippine Constabulary and Integrated National Police provincial commands. These 73 provincial headquarters in turn supervised 234 constabulary companies, which were the constabulary's line units. Regional Special Action Companies provided backup to the line companies and acted as counterinsurgency strike forces. An additional area command, known both as Capital Command and the Metropolitan Police Force, directed Philippine Constabulary and Integrated National Police elements in Manila. Metropolitan District Commands performed a similar function in eight of the nation's other major urban areas.

The constabulary also had a variety of specialized units with nationwide responsibilities that operated independently of the regional command system. These included the Criminal Investigative Service, Highway Patrol Group, Security Group, Crime Lab, and Support Command. The Philippine Constabulary Training Command was responsible for instructing enlisted constables and their officers, whose training paralleled that of the army. In 1983 the constabulary created an elite national reaction force, the Philippine Constabulary Special Action465 on Force, with the capability to combat terrorism, hijacking, and insurgency. These additions contributed to the overall growth of members of the constabulary during the 1980s, from approximately 33,500 in 1980, to an estimated 45,000 members in 1990.

On January 1, 1991, the Philippine Constabulary and the Integrated National Police were combined to form the Philippine National Police. The Philippine National Police took immediate responsibility for most former Integrated National Police functions, including fire and jail services, and was to assume responsibility for the counterinsurgency effort from the AFP after two years, in 1993. Few details were available at the end of 1990 on how the military planned to effect the transfer of police and, ultimately, counterinsurgency responsibilities to civilian control.

Data as of June 1991