ComStar, known also as the ComStar Order or simply "the Order," is an interstellar organization charged with maintaining the Hyperpulse Generator network, the primary means by which interstellar communication is conducted in the BattleTech universe. With the collapse of the Star League, Minister of Communications Jerome Blake anticipated that the upcoming Succession Wars would not only destroy the network, but also destroy the wealth of knowledge and technology humanity had accumulated over the centuries. With the agreement of the Successor States, ComStar was given monopolistic control of the HPG network, with Terra serving as its headquarters and the organization presenting itself as a neutral arbiter in the conflicts. ComStar issued its own Letter of Credit - the C-Bill - which soon became the standard in interstellar commerce; the ComStar News Bureau was created ostensibly to provide news service across the Inner Sphere; and the Mercenary Review Board was formed as an 'honest broker' for the booming mercenary industry. Much of the knowledge which became lostech in the rest of the Inner Sphere was preserved in secret by ComStar.
Beneath its benign, pacifistic façade though, ComStar itself was an antagonistic player in the Succession Wars, pitting the sides against each other for its own purposes. The shrouds of secrecy which had been necessary during ComStar's early years developed into a mystical religion, at the fore of which was the belief that ComStar had a holy duty to save humanity from itself by taking control of all knowledge and power.
The ComStar Guards and Militia, later renamed Com Guards, was the military arm of ComStar. Kept hidden by the supposedly politically neutral organization until after the Fourth Succession War, the Guards were a force on par with the militaries of the Successor States. Originally serving as clandestine black ops forces, then garrison troops for ComStar's HPG compounds, they eventually shifted towards a role as defenders of the Inner Sphere, most famously their victory against the Clans in the Battle of Tukayyid.