Tjokronegoro (regent of the Ponorogo Regency), and great-grandson of Kyai Bagus Kasan Besari of Tegalsari pesantren.

[1] He moved to Surabaya, where he met Samanhudi, founder and leader of the Islamic Trade Unions (SDI).

His political ideas also gave birth to various ideologies of Indonesia at that time, when he tutored students in his household, such as Semaoen, Alimin, Musso, Sukarno, Kartosuwiryo, and even Tan Malaka.

After he died, the colors of the Indonesian movement were developed by his students, the socialists and communists embraced by Semaoen, Musso, and Alimin.

One of his most famous quotes was "Highest education, purest tauhid, smartest of strategies" (Indonesian: Setinggi-tinggi ilmu, semurni-murni tauhid, sepintar-pintar siasat), depicting the atmosphere of Indonesian struggle in its time which required the three aforementioned abilities of a freedom fighter.

In explaining the organization's aim, Tjokroaminoto stated that SI would not oppose the Dutch East Indies government.

The usage of the word national signified the issue Tjokroaminoto had voiced, which was the necessity of unity of all Indonesians.

SI gained acknowledgment of its power with the inauguration of Tjokroaminoto and Abdoel Moeis as members of the newly opened Volksraad in 1918.

Eventually, the Marxist–Leninist faction broke off and formed SI-Merah ("Red-SI"), which later joined the Communist Party of Indonesia.

[clarification needed] After propaganda attacks were sent, insurgency broke out wherever, until he and Abdoel Moeis were forbidden to visit some areas.

The political suggestion of hijra or "migration" with the non-cooperative attitude toward the colonial government was eventually accepted by Congress, which caused Tjokroaminoto's refusal when he was elected as Volksraad's member in 1927.