His father, Bernard Heidenreich Thomson, was a navy medical officer of British origin, while his mother a member of the noble Pompe van Meerdervoort family.

[1] Thomson joined the army in 1884, and studied at the Koninklijke Militaire Academie in Breda, holding the rank of a second lieutenant of the infantry.

Between 1894 and 1896, he served in the Dutch colonial forces and took part in the Aceh War, where he was awarded the grade of a Knight 4th class of the Military Order of William.

In 1914, now holding the rank of major, he was selected as head of the new International Gendarmerie force which was to work under the command of Dutch officers in Albanian service in a peacekeeping function to stabilize the newly independent Principality of Albania.

As a reaction to Thomson's death and the general failure of the peacekeeping project, the Dutch activity in the Albanian gendarmerie was discontinued a short time later.