af Wirsén became a second lieutenant in the Svea Life Guards in 1895, was promoted to lieutenant in 1897 and attended the Royal Swedish Army Staff College from 1900 to 1902.
He was acting extra second legation secretary in Warsaw from 15 January to 31 March 1921 and was appointed acting extra first legation secretary at the Ministry for Foreign Affairs on 8 April the same year [REF].