Before beginning his career, he studied at Westminster City & Guilds College and the Royal Academy Schools.

He enlisted in the Royal Flying Corps in 1915, but for medical or other reasons was put on the reserve until 1917 when he served at the School of Military Aeronautics and subsequently made Lieutenant.

[nb 1] Louis Roselieb attended Westminster City & Guilds College before entering the Royal Academy Schools, where in 1905 he was won a two year Landseer Scholarship for sculpture.

It is not entirely clear when this decision was made; the statue of Edward VII had been done under the name Roselieb in 1911, whereas his work on the Imperial Buildings in 1914 was signed Roslyn.

[3] Having enlisted, Roselieb was put on the reserve, and in June 1917 was called to the School of Military Aeronautics, Royal Flying Corps, Reading, as an Equipment Officer, 3rd Class on probation.