On June 15th, 1962 the International Court of Justice (ICJ) ruled in favor of Cambodia as Preah Vihear’s rightful owner in a long standing land dispute between Thailand and Cambodia. Today (in Cambodia) marks the 58th anniversary of this event.
In 1904, Siam and the French colonial authorities ruling Cambodia formed a joint commission to demarcate their mutual border to largely follow the watershed line of the Dangrek mountain range, which placed nearly all of Preah Vihear temple on Thailand’s side. In 1907, after survey work, French officers drew up a map to show the border’s location. However, the resulting topographic map, which was sent to Siamese authorities and used in the 1962 (International Court of Justice (ICJ) ruling, showed the line deviating slightly from the watershed without explanation in the Preah Vihear area, placing all of the temple on the Cambodian side.
Following the withdrawal of French troops from Cambodia in 1954, Thai forces occupied the temple to enforce their claim. Cambodia protested and in 1959 asked the ICJ to rule that the temple and the surrounding land lay in Cambodian territory. The case became a volatile political issue in both countries. Diplomatic relations were severed, and threats of force were voiced by both governments.
In full here.