Glenlyon is a sovereign planet, which is a full member of the Alliance. It is the home planet of the Geary family, of which the most renowned member is the commander of the Alliance First Fleet, Admiral John Geary. As is required of all Alliance members, Glenlyon is a democracy that contributes its share of the Alliance budget and contributes people to the Alliance military, but little more about its government is known.

It is mentioned that Glenlyon has vast rolling fields.