A Galaxy is the largest type of military formation fielded by the Clans, equivalent to a brigade in the defunct Star League Defense Force. Named for a letter of the Greek alphabet (e.g. "Alpha", "Delta", "Omega"), a Galaxy consists of several Clusters and is commanded by a Galaxy Commander. Galaxies are self-contained units which include all the necessary assets to mount independent operations, though in practice Galaxies rarely take to the field of battle as one unified force.
Some Galaxies can have as few as two Clusters, while others can have as many as six. Most Galaxies will have three to five Clusters and include an independent command Trinary or Cluster.
Nicholas Kerensky himself intended for Galaxies to serve as administrative and logistical organizations rather than as battlefield units, and unlike smaller formations never set down criteria for their composition. Support elements such as engineers, artillery and MASH units are organized at the Galaxy level but can be attached to individual Clusters as needed.