From the back of the book:
Precariously poised between the fierce eagle of House Marik and the voracious dragon of House Kurita, House Steiner fights a desperate battle to protect the worlds, industries, and peoples of the Lyran Commonwealth. One of the five Successor States of the fallen Star League, the Commonwealth is noted for having the strongest economy and the weakest military leadership of all the realms. Nevertheless, its clenched fist is a symbol of defiance to those who would swallow the Commonwealth whole.
Compiled from ComStar records comes this sourcebook on the Lyran Commonwealth and House Steiner. Included are dozens of full-color illustrations depicting Commonwealth rank insignias, unit crests, medals, personalities, and more. Classified documents on the Lyran Commonwealth Armed Forces' deployment from the Tamar Theater to Tharkad, military structure, and political intrigues are also provided. The extensive history section stretches from Terra's first steps into interstellar space to Melissa Steiner's betrothal to Hanse Davion.