He was born in Herøy as a son of Peter Vilhelm L'orange (1806–1871) and Ingeborg Bue.
He had reached the rank of premier lieutenant in 1857, and attended the Norwegian Military College before he was a brigade aide-de-camp in Bergen and from 1864 an apprentice in the General Staff.
He was the leader of the Norwegian Military Academy from 1872 to 1885, and also lectured in topography and wrote the textbook Veiledning i Terrænget.
He reached the ranks of captain in March 1867, major in July 1885, lieutenant colonel in January 1889, colonel in February 1891, and major general in April 1894, lastly Lieutenant General from July 1899.
[3] He was decorated with the Grand Cross of the Royal Norwegian Order of St. Olav in September 1903.