He joined his father in the Swedish Army, serving as an ensign in Herman Wrangel's Kronoberg regiment in 1623.
Ruthven became a colonel in June 1631 and he was appointed Governor of Memell in 1633 during its occupation by Swedish forces.
He was a Royalist and likely returned to Scotland before or during the Civil War, but is not recorded as playing any role in the conflict.
On 11 July 1666 he was created a baronet, of Redcastle in the Baronetage of Nova Scotia.
[2] Ruthven's title became extinct upon his death without male heirs.