After starting as a notary at the Svea Court of Appeal in 1889, he quickly rose through the ranks, becoming second secretary in the Ministry for Foreign Affairs in 1896 and later serving as deputy director and head of its Consular Department in 1903.

He held key positions as envoy extraordinary and minister plenipotentiary in Constantinople, where he was an eyewitness to the Armenian genocide, and later in Warsaw, where he served until 1931.

Anckarsvärd was appointed chamberlain to the Royal Court of Sweden on 9 June 1899 and served as herald in the Order of the Seraphim (Kungl.

On 28 September 1906, Anckarsvärd was named envoy extraordinary and minister plenipotentiary to Constantinople (now Istanbul), while also serving as consul general there.

[2] During the events, Anckarsvärd highlighted the aim of the Young Turk government and its policies to "exterminate the Armenian nation".