Van Daalen was named after his Dutch father, Gotfried Coenraad Ernst (Frits) van Daalen, who was born in 's-Hertogenbosch, the Netherlands on 23 July 1836 and died in Surabaya on 13 May 1889), who was also a famous, decorated KNIL officer and a veteran of the Aceh War and who was discharged from service as a consequence of a scandal in which he publicly offended the Governor-General of the colony.

As a young officer with the rank of lieutenant and captain, van Daalen was awarded several prestigious military distinctions for proven bravery.

Particularly, the battle at Koetö Réh, which was built by the Alas people, stood out, as the rebels refused to surrender, and the death toll of 561 fighters included 189 women and 59 children.

[2] The press reported on the death toll,[4] and it later published images of the brutal warfare in Aceh that shocked Dutch public opinion.

[2] In the heated debate, van Daalen himself was compared to the Iron Duke of Alba, a Spanish ruler who was notoriously harsh and cruel from Dutch national history.