He served as a Swedish envoy in Venezuela (1948–1953) with dual accreditation to a number of countries in the Caribbean, as well as ambassador to Greece (1956–1962) and Switzerland (1962–1965).
[2] Stackelberg attended the Royal Military Academy in Stockholm in 1919 and served as a second lieutenant in the Svea Artillery Regiment (A 1) from 1920 to 1922.
[3] Stackelberg received a Candidate of Law degree in Stockholm in 1925 before becoming an attaché at the Ministry for Foreign Affairs the year after.
He served in Copenhagen, Bern, London, Vienna, Budapest and Belgrade from 1926 to 1930 and was lieutenant at the Svea Artillery Regiment's reserve from 1928 to 1929.
[3] Stackelberg was representative at the trade negotiations with Denmark from 1947 to 1948 and was envoy in Caracas, Havana, Ciudad Trujillo and in Port-au-Prince from 1948 to 1953.