Umar received the title "panglima prang besar" (upper warlord of the government). Umar called himself rather "Teuku Djohan Pahlawan" (Johan the heroic). On January 1, 1894 Umar even received Dutch aid to build an army. However, two years later Umar attacked the Dutch with his new army, rather than aiding the Dutch in subjugating inner Aceh. This is recorded in Dutch history as "Het verraad van Teukoe Oemar" (the treason of Teuku Umar). In 1892 and 1893, Aceh remained independent, despite the Dutch efforts. Major J.B. van Heutsz, a colonial military leader, then wrote a series of articles on Aceh. He was supported by Dr Snouck Hurgronje of the University of Leiden, then the leading Dutch expert on Islam. Hurgronje managed to get the confidence of many Aceh leaders and gathered valuable intelligence for the Dutch government. His works remained an official secret for many years. In Hurgronje's analysis of Acehnese society, he minimised the role of the Sultan and argued that attention should be paid to the hereditary chiefs, the "Ulee Balang", who he felt could be trusted as local administrators. However, he argued, Aceh's religious leaders, the ulema, could not be trusted or persuaded to cooperate, and must be destroyed. This advice was followed: in 1898 Van Heutsz was proclaimed governor of Aceh, and with his lieutenant, later Dutch Prime Minister Hendrikus Colijn, would finally conquer most of Aceh. They followed Hurgronje's suggestions, finding cooperative "uleebelang" that would support them in the countryside. Van Heutsz charged Colonel Van Daalen with breaking remaining resistance. Van Daalen destroyed several villages, killing at least 2,900 Acehnese, among which were 1,150 women and children. Dutch losses numbered just 26, and Van Daalen was replaced by Colonel Swart. By 1904 most of Aceh was under Dutch control, and had an indigenous government that cooperated with the colonial state. Estimated total casualties on the Aceh side range from 50,000 to 100,000 dead, and over a million wounded. During World War I the Netherlands remained neutral. A large army was mobilised to defend this neutrality, but it was not equipped by the new standards of the day, causing a structural equipment inferiority that would last until the middle of the century.