Pailin province: History
Pailin was founded during the Khmer Empire, where it existed as an important trading center. It continued its role as a center of trade and commerce under French colonial rule, which saw the establishment of French-operated stores and plantations. Between the late 19th century to the early 20th century, the area saw an influx of multi-ethnic Burmese immigrants from Mogok and other areas of Burma who became collectively known as the Kula people. The Kula settled around Pailin and built various structures based on traditional Burmese architecture. In the 1870s, various sapphire and ruby veins in the area began to be discovered. The reason for Burmese attraction to the area was due to the alkali basalt volcanic origins of Pailin's Phnom Yat deposit which mirrored that of Mogok's gem fields. Archival collections had stated that the Kula elite had created a "state within a state" by the 1890s; instead of relying on subsistence agriculture, Pailin's miners had imported products from abroad.
Under Siamese rule, Pailin's gem industry was exploited on a major scale. The Siam Exploring Company reported that monopoly extraction rights were given to British firms and subcontracted to Burmese operators such as Maung Soy. According to a scientific study done by the Gemological Institute of America (GIA), around 90% of the world's fine sapphire productions were from Pailin until the area's transfer to French Indochina. Up until the early 1970s, Pailin was a prosperous region stemming from its extensive gem deposits. During that time it was one of the most popular destinations for tourists and businessmen from around Cambodia.
Due to its resources, it was one of the first areas sought after by the Khmer Rouge when they began their major offensive against the Khmer Republic government. Pailin remained one of the last major strongholds of the Khmer Republic government extending a few days past the Fall of Phnom Penh. Some residents had took to this window to flee Cambodia due to Pailin's proximity to the Thai border after hearing of the Khmer Rouge's actions from refugees escaping other cities. Pailin was captured by the Khmer Rouge on April 20, 1975 with little to no resistance since Khmer Republic soldiers had departed the city. In only a few days, residents were rounded up for a forced march to the countryside to work in rice paddies. Those believed to have connections to the government were killed. The Khmer Rouge used proceeds from mining in the Pailin area to fund their offensive and later their government once they gained national power. When the invading People's Army of Vietnam ousted them from power, they retreated to Pailin, where many former Khmer Rouge leaders remain today. It was the capital of the Provisional Government of National Union and National Salvation of Cambodia.
Some leaders went into hiding in fear of punishment for their crimes, although other leaders lived openly in the province. As of September 2007, Pailin's remaining Khmer Rouge leaders were being rounded up to face justice by an international tribunal, including Khieu Samphan and Nuon Chea.
Since the war, Pailin had suffered an economic decline and failures of local businesses. However, the now politically stable area is seeing a new wave of tourism focused on its ancient temples, natural forests, and wildlife, and especially its gem markets.