In the fictional BattleTech universe, the Successor States are the major military powers of the Inner Sphere, each governed by one of the Great Houses. Each Successor State has its own culture and customs,

The Successor States

Federated Suns

Capital world, New Avalon.

Notable characters

• Hanse Davion
• Justin Allard

Draconis Combine

Strongly influenced by Japanese culture.
Capital world, Luthien.
The Free Rasalhauge Republic (FRR) was once part of the Draconis Combine.

Notable characters

• Hohiro Kurita
• Omi Kurita
• Theodore Kurita
• Yorinaga Kurita

Capellan Confederation

Strongly influenced by Chinese culture.
Capital world, Sian.

Notable characters

• Maximillian Liao
• Sun-Tzu Liao

Free Worlds League

Capital world, Atreus.

Notable characters

• Thomas Marik

Lyran Alliance

Capital world, Tharkad

Notable Characters

• Melissa Steiner

Federated Commonwealth

The Federated Commonwealth came into being with the marriage of Hanse Davion and Melissa Steiner, joining the Federated Suns and the Lyran Alliance into what was now the most powerful of the Successor States. Unfortunately, the Federated Commonwealth was torn apart by Hanse and Melissa's children; Victor and Katherine.
Capital worlds, Tharkad and New Avalon.

Notable characters

• Katherine Steiner-Davion
• Victor Steiner-Davion
• Kai Allard-Liao

ComStar

While not strictly being one of the Successor States, ComStar is politically influential, as it maintains a monopoly over the HyperPulse Generators, which are crucial to interstellar communication; the threat of a communications blackout makes ComStar a significant power within the Inner Sphere. ComStar itself is composed of quasi-mystical technicians who tend the HPG arrays. They profess to be neutral to the politics of the Inner Sphere. Jerome Blake is something of a religious figure to ComStar; oaths such as "By the blessed Blake" or epithets such as "Blake's Blood!" are not uncommon. Jerome Blake was the original founder of ComStar, after the Star League fell, and is considered by those within ComStar to be the savior of the Inner Sphere.
Capital, and only world, Terra.

The story of ComStar is heavily influenced by Isaac Asimov's Foundation books.

Notable characters

• Anastasius Focht
• Jerome Blake
• Julian Tiepolo
• Myndo Waterly

Mercenaries

Also not truly a Successor State, mercenaries play a large role in the Inner Sphere, and some of the larger groups have considerable political influence and military might.

Notable characters

• Jamie Wolf
• Morgan Kell
• Phelan Kell