Born in a low-priyayi family and educated in the Dutch system, Kartosuwiryo was to become a prominent political proponent of anti-colonialism and anti-Western ideologies. He soon gained the attention of authorities for his work as a journalist and the attention of Tjokroaminoto for his political engagement. And while the former accused him of fanaticism, the latter reared him as a godson.
Gradually shifting his attention from socio-economic concerns towards Islamic modernism, from condemning the colonial state for ignoring the importance of religion in Indonesians’ lives to accusing secular nationalists of doing the same in politics, Kartosuwiryo’s own development mirrored the changes in the Sarekat Islam party. Initially incorporating socialists and Islamists and embodying this double soul in its leader, Tjokroaminoto, Sarekat Islam had clearly defined itself as an Islamic political party in opposition to Soek- arno’s secularism and Semaoen’s socialism by the end of the 1920s. Exposed to international dynamics originating both in Europe and the Middle East, regional and ethnic cultural organizations were transformed into political parties that were increasingly defined by their founding ideologies.
Kartosuwiryo’s dedication to gathering popular support in the countryside, fostering the urban youth as ‘perfect Muslims’, and creating new family connections in order to be recognizable as a bearer of local and traditional authority were all key elements in his leadership in subsequent decades. As the Dutch curbed political activities, the anti-colonial front became increasingly fragmented, with each party further radicalizing its position.