Oemar Said Tjokroaminoto

Oemar Said Tjokroaminoto (16 August 1882 – 17 December 1934), better known in Indonesia as H.O.S. Tjokroaminoto, was an Indonesian nationalist. He became one of the leaders of the Islamic Trade Union, founded by Samanhudi, which became Sarekat Islam, which they both cofounded. Early life Tjokroaminoto was born the second of twelve children, in the Ponorogo Regency as the son of RM. Tjokroaminoto (district chief of Kleco), grandson of RMA. Tjokronegoro (regent of the Ponorogo Regency), and great-grandson of Kyai Bagus Kasan Besari of Tegalsari pesantren. According to his genealogy, his education was directed towards civil service. After graduating in 1902 from OSVIA, a school for indigenous civil servants, in Magelang, the then-highest civil servant education institution, he worked as one in Ngawi for three years from 1902 to 1905). He moved to Surabaya, where he met Samanhudi, founder and leader of the Islamic Trade Unions (SDI). At night, he attended Burgerlijke Avond School (BAS) for some years. After graduating, he worked in a sugar refinery (1907–1912). He wrote for the Bintang Soerabaja (Surabaya Star) daily and became a staff assistant. Known as the "Crownless King of Java" by the Dutch, Tjokroaminoto was one of the pioneers of the trade union movement in Indonesia and was a teacher of some of the most well-known leaders of Indonesia. His political ideas also gave birth to various ideologies of the Indonesia at that time, where he tutored students in his own household, such as: Semaoen, Alimin, Musso, Sukarno, Kartosuwiryo, and even Tan Malaka. He was the first to refuse to submit to the Netherlands. After he died, the colors of the Indonesian movement were developed by his students, the socialists and communists embraced by Semaoen, Musso, and Alimin.