The province has an area of 147,307 km² with a recorded 2010 census population of 4,393,239. Major ethnic groups include the Dayak, Malay, Chinese, which make up about 90% of the total population. Other groups include the Javanese, Bugis, and Madurese.
The borders of West Kalimantan roughly trace the mountain ranges surrounding the watershed of the Kapuas River, which drains most of the province.
The history of West Kalimantan can be dated back to 17th century. Dayaks were the main inhabitants of the province before 17th century. The Malay migrated to West Kalimantan and built their own sultanates. The high Chinese population in this province was due to a republic founded by Chinese miners called Lanfang Republic after they defeated the local Malay sultans. The government of Lanfang Republic was ended in West Kalimantan after the Dutch occupation in 1884.
West Kalimantan was under Japanese occupation from 1942 to 1945, when Indonesia declared its Independence. During the Japanese occupation, more than 21,000 people in Pontianak (including sultans, nobleman, women and children) were kidnapped, tortured and massacred by Japanese troops. Japanese intelligence had become concerned that the ethnic Chinese were planning to start a rebellion, and were worried that people in the city had received guns and ammunition from the Chinese government.
The massacre occurred from April 23, 1943 to June 28, 1944 and most of the victims were buried in several giant wells in Mandor (88 km from Pontianak). Allied forces occupying the area after the war found several thousand bones, and more than 60 years after the massacre, several secret graves of the victims were found in Mandor and the surrounding areas.
After the end of war, the Japanese officers in Pontianak were arrested by allied troops and brought in front of an international military tribune. During the trial, it was revealed that the plan to start the rebellion did not exist and instead was only an imaginary plan created by Japanese officers who wanted to get promoted.
A monument called Makam Juang Mandor was created to commemorate this tragic event.
During the 1930s the Dutch colonial powers initiated a "transmigration plan" to move people from heavily populated islands such as Java, to the less populated islands of Irian Jaya and Kalimantan. In the 1960s the Indonesian government granted the Madurese rights to clear lands from forest for palm oil cultivation. This conflicted with the local Dayak tribes’ traditional way of life. The tensions between the two ethnic groups resulted in major eruptions of violence in 1996, 1999 and 2001, resulting in about 500 deaths.