When the last Americans depart Clark Air Base next year, they will be leaving one of the largest U.S. military installations abroad, a place steeped in history.

Clark was the scene of heavy fighting in World War II, and the place where returning American prisoners of war tasted their first freedom at the end of the Vietnam War.American and Philippine negotiators recently announced agreement on a plan for the U.S. Air Force to give up the base in September 1992, but keep the American naval base at Subic Bay for 10 more years.

The United States had hoped to retain Clark, until the base was devastated last month by the eruptions of Mount Pinatubo, a volcano 10 miles to its west.

Clark is one of the oldest American bases on foreign soil.

Set on the fertile plains of central Luzon island, 50 miles north of Manila, it was first used as a military outpost in 1901 when American forces crushed a Philippine bid for independence. Horses from the U.S. 5th Cavalry grazed in the rich pasture lands.

Two years later, President Theodore Roosevelt formally established the base and named it Fort Stotsenburg after Col. John M. Stotsenburg, a military leader who was killed in the Philippine-American war.

In 1917, an airfield was added to the base and was named Clark Field in memory of Maj. Harold M. Clark, a pilot who was killed in a 1919 crash in the Panama Canal zone.

When World War II broke out in the Pacific in December 1941, Clark Field and Fort Stotsenburg were home to the 26th Cavalry and the 24th Field artillery and air units, including the 19th Bombardment Group.

Japan raided the field soon after its warplanes attacked Pearl Harbor on Dec. 7, 1941. The raid destroyed enough American planes to enable Japanese troops to invade Luzon and defeat a combined U.S. and Filipino force.

During the Japanese occupation, the base was used by the Japanese 201st Air Group until the allied forces recaptured the area in 1944.

After the war, the Philippines was granted independence and signed an agreement with the United States allowing U.S. forces to use the base and several others here.

In 1947, Clark Field and Fort Stotsenburg were combined and renamed Clark Air Base.

During the early 1950s, U.S. forces from Clark were sent to the Korean War. Clark became headquarters for the 13th U.S. Air Force, which directed all American air operations in Southeast Asia.

In 1973, American POWs were flown from Hanoi to Clark as part of "Operation Homecoming" before they were sent on to the United States.