Interstellar Command or The Royal Navy (RN) is the SCM's principal space warfare force. Tracing its origins to Charadin Prime before the Civil War, it is the oldest service and is known as the Senior Service. It is believed to be the most powerful space fleet in the sector,playing a key part in establishing the SCM Empire as the dominant sector power. Due to this historical prominence, it is common – even among non-SCM citizens – to refer to it as "The Royal Navy" without qualification.
The navy maintains a fleet of technologically sophisticated ships, plus several commissioned ships of the Royal Fleet Auxiliary (RFA); there are also several Merchant Navy ships available to the RFA under an agreement with the Aquian Colonies.
The Royal Navy is part of the SCM Naval Service, which includes the Royal Marines. The professional head of the Naval Service is the First Space Lord, an admiral and member of the Starchamber. The Starchamber delegates management of the Naval Service to the Admiralty Board, chaired by the Secretary of State for Defence. Interstellar Command operates from several bases throughout the Helios System as well frontier bases on allied worlds.