[2] In 1881, he was commissioned second lieutenant at the military engineers of the Royal Netherlands East Indies Army (KNIL).

[1] In 1903, he passed the Decentralisation Law which allowed the East Indies to established independently financed regional councils.

[1] During his tenure, he developed the "Idenburg Plan" in order to achieve financial independence for the colony, however it did not pass.

[2][8] Van Daalen had lost twelve men during the Aceh Wars, but – as is now known – to have caused at least 2,922 native deaths including at least 1,149 women and children.

[2] In 1913, Idenburg interned the journalist Ernest Douwes Dekker (a relative of Multatuli)[11] for founding the Indische Party.

[2] In September 1913, Douwes Dekker was exiled from the Dutch East Indies and not allowed to travel to the Netherlands either.

[13] Idenburg tried to pass a Sunday Law in the Dutch East Indies, but only managed a watered down version.

[1] On 9 September 1918, Idenburg was reappointed as Minister of Colonies, but resigned on 13 November 1919[1] due to health problems.