The Concordiat of Man was an interstellar power founded by humans. It was the not the original creator of Bolos, but Bolos were a mainstay throughout its history. The Concordiat designed and produced Bolos, starting with the Bolo Mark IV, and continued doing so until the Bolo Mark XXXIII, the last Bolo design produced before the collapse of the Concordiat.
Due to worsening relations between the Concordiat and the Quern Hegemony from 2880 to 2918, bolo research was driven forward at breackneck speed. The Bolo Mark XXIII was ready just before the Quern launched a surprise attack. The Concordiat was able to win the war, but there was still heavy damage among frontier worlds, such as Santa Cruz.
Six months after first contact between the Melconian Empire and the Concordiat in the 3200's, the Melconians slammed down a Non-intercourse Edict. It was standard for the Melconians to do this with any new species they encountered until the newly discovered species could be evaluated. Unfortunately, to the Concordiat, this appeared to be a hostile act. Misunderstandings on both sides led to increasing tensions until the shooting war started in the Battle of the Trellis System in 3343. The war continued for 208 years until both sides destroyed each other.
The core of the Concordiat military was its Bolos. From the Mark IV in the beginning, to the Mark XXXIII , at its final hour. It also had a number of lighter manned tanks to supplement its Bolos such as the Wolverine heavy tank of the Quern wars or the Golem series eighty years later.