Van Daalen was named after his Dutch father Gotfried Coenraad Ernst (Frits) van Daalen (born in 's-Hertogenbosch, the Netherlands 23 July 1836 and died in Surabaya, 13 May 1889), also a famous, decorated KNIL officer and veteran of the Aceh War, who was discharged from service as a consequence of a scandal where he saw fit to publicly offend the Governor-General (highest colonial authority) of the colony.
As a young officer in the rank of Lieutenant and Captain Van Daalen was awarded several prestigious militairy distinctions for proven bravery. He first became Knight of the Military William Order in 1890, was awarded the Honorary Sabre by the Dutch monarch in 1897, followed by becoming an Officer of the Military Willem Order in 1898.
Although notorious due to his controversial approach during the final phases of the protracted Aceh War and his consequent conflicts with both Van Heutsz and Snouck Hurgronje, he was appointed Governor of Aceh between 1905 and 1908.
He was eventually promoted to the highest rank of Luitenant-generaal in 1909 and became Commander of the KNIL in 1910, before retiring and repatriating in 1914.
Van Daalen's "Gajo-, Alas-, and Batak Campaign" of the Aceh War in 1904 is mostly remembered for his hard crack down of the last Acehnese and Batak pockets of resistance. Van Daalen's force included 10 European officers, 13 European non-commissioned officers and 208 Javanese and Ambonese military police officers (Dutch: Marechaussee). Particularly the battle at Koetö Réh stood out, as the rebels refused to surrender and the death toll of 561 fighters included 189 women and 59 children.
Through the Dutch press many confronting stories and images of brutal warfare in Aceh reached the colonial metropole and shocked Dutch public opinion. Heavy critique from the Dutch House of Representatives called for an investigation into the alleged atrocities and damaged the KNIL's overall prestige. In the heated debate Van Daalen himself was compared to the Iron Duke of Alba, a notoriously harsh and cruel ruler from Dutch national history. Although absolved from any crimes, Van Daalen's reputation remained stained and all his subsequent promotions were therefore contentious.
Still with support from the hawks and hard liners the career of the old war horse flourished and he became Governor of Aceh and was promoted to the highest rank and office in the colonial 'KNIL' Army. Although unusual his military career shows that it was not impossible for Indo-Eurasians to attain positions at the top of the colonial hierarchy of the Dutch East Indies.