In the BattleTech universe, the Successor States (named as such due to their being the "Successors" of the Star League) 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 Great Houses of the Successor States
 House Davion
Strongly influenced by Great Britain, United States, and France.
Capital world: New Avalon
The Federated Suns is an interstellar nation set within the BattleTech game universe, introduced by FASA Corporation in the 1980s. The Federated Suns have been ruled by the Davion Family, or House Davion, since the nation's founding in 2317.
The FedSuns was founded in 2317 by Lucien Davion, Prime Minister of New Avalon, when he negotiated a mutual defense and assistance agreement, known as the Crucis Pact, with 20 nearby star systems. Lucien became the federation's first president and New Avalon its capital. A member of the Davion family has led the Federated Suns in unbroken succession for the past 700 years. Presently on the throne is Yvonne Steiner-Davion, youngest sister to the former ruler, Victor Steiner-Davion. Both are children of Hanse Davion and Melissa Steiner, whose marriage effectively sealed the Federated Suns' alliance with the Lyran Commonwealth. The Federated Suns claim approximately 400 inhabited star systems under its aegis, nearly double the number of worlds controlled at the beginning of the Succession Wars. In addition, uncounted other worlds are claimed and exploited by Davion forces.
Much of House Davion's growth over the past 200 years has taken place at the expense of Liao's Capellan Confederation. This was particularly true at the end of the Fourth Succession War, when the Federated Suns took more than 100 worlds from House Liao.
An even more serious enemy to the Federated Suns has been the Draconis Combine, ruled by House Kurita, which nearly succeeded in conquering the Davion realm during the First Succession War. By forging an alliance with the Lyran Commonwealth in 3022, Davion forced Kurita to spread its 'Mech resources along two frontiers, leaving many worlds thinly defended. Prior to the Fourth Succession War, Davion forces were able to exploit this vulnerability, seizing the Combine worlds of Tancredi II and Galatea, as well as Star League storehouses at Galtor and Rowe, while losing very few units themselves. With the outbreak of war, however, the Federated Commonwealth had to rearrange its priorities. By the end of the Fourth War, House Kurita had managed to seize 15 worlds, including Galtor, along its border with House Davion.
Surprisingly, the Clan threat has done much to destroy the traditional Davion-Kurita rivalry. There is even rumor of a love affair between Victor Steiner-Davion and Theodore Kurita's daughter, Omi Kurita, although official sources consistently deny the connection. It is known that Victor Davion led a mission to a Clan-held world to rescue Theodore Kurita's son, Hohiro Kurita (the younger). With the Clan threat diminishing for a time, tensions will no doubt resurface. Clashes, at least minor ones, between Davion and Kurita forces will recur.
Common Nicknames: Davionist
 Notable characters
 House Kurita
Strongly influenced by Japanese culture.
Capital world: Luthien.
In the BattleTech universe, House Kurita is the ruling family of the fearsome Draconis Combine. The only Great House that proclaims unabashedly its right to rule all of the Inner Sphere, House Kurita has dominated the Draconis Combine since its founding in 2319. Its progenitor was Shiro Kurita, the first Coordinator of the Draconis Combine. The current Lord of House Kurita is Coordinator Theodore Kurita, who succeeded his father Takashi Kurita in 3054. House Kurita has had a long history of antagonism with and aggression against its neighbors. Though its official symbol is the serpentine Chinese dragon, humorist Homer Kellogi thought the octopus a more appropriate symbol, since House Kurita's tentacles are everywhere. Though driven by an archaic sense of honor spelled out in the Dictum Honorium, House Kurita is not above using subterfuge and guile to further its goals.
A massive tome comprising many volumes, the Dictum Honorium would require several lifetimes to master. It spells out in fine detail the code of conduct for all citizens of the Draconis Combine, from the Coordinator to his Samurai to the lowest Unproductive. Due to its length and general impenetrability, few manage to read more than a few pages, and the Dictum has little actual effect on daily life. Several passages, such as the special rules allowing the taking (instead of summary execution) of prisoners of war valuable to military intelligence and ransom are kept secret from the public.
Common Nicknames: Kuritan
Pejoratives: Drac, Draco, Snake
 Notable characters
 House Liao
Strongly influenced by Chinese, Russian, and Scottish culture.
Capital world: Sian
The Capellan Confederation has long been considered the underdogs of the Inner Sphere, known for mentally unstable leaders that are often violently oppressive towards their own people and great military losses in each succession war leading them to a shadow of their former size.
However, in more recent years, the Capellan Confederation has strengthened incredibly under the leadership of Sun-Tzu Liao. Often manipulative but the best leader the empire has seen in years, the Confederation has a strong alliance with the Free Worlds League, resulting in rapid technological increase, as well a social reformation among the people (known as Xin Sheng) restoring their pride. This culminated in the Confederation re-taking a pocket of territory on the Davion border known as the St. Ives Compact which revolted with Federated Commonwealth help in the 4th Succession War, during Sun-Tzu's grandfather's rule.
More recently the Confederation has gained strong alliances with both major Periphery factions on its borders, giving it access to the rear guard of both the Free Worlds League and Federated Commonwealth (Federated Suns in the post civil war era), as well as strong but technologically inferior military allies. This leaves the Confederation as one of the strongest factions in the post-civil war classic period.
 Notable characters
 House Marik
Multicultural, with strong European, American, and Indian overtones.
Capital world: Atreus
The Free Worlds League is notable as the first successor state founded in the Inner Sphere. While their history is wracked with many vicious civil wars and tensions along the Liao border, much of the Leagues territory there originally belonged to the Capellan Confederation. The dawn of the Clan invasion changed their role in the galaxy considerably as one of the two untouched nations and, until Operation Serpent, neutral factions in the war.
This led the Free Worlds League to becoming an economic powerhouse, supplying materials ranging from food to 'Mechs, to other factions in need; often trading for advanced Clan technology. During this time the split between the Word of Blake and Comstar impacted the League as well, making them the first House to remove Comstar from control of House communications, in favor of the Blakeists.
The Free Worlds League has a strong emphasis on combined arms tactics, with almost all of their regiments featuring a large number of infantry, armor and aerospace assets, as well as one of the largest navies in the Inner Sphere. The focus on 'Mechs, however, does exist within their elite regiments that make up the Knights of the Inner Sphere, in an effort to return to Star League tradition of minimizing loss of life by reducing war to just a handful of combatants. Near the end of 3067, the Free Worlds League had a space navy that greatly outpaced those of the other Successor States.
After the Word of Blake Jihad, the Free Worlds League dissolved and is now a defunct power.
 Notable characters
 House Steiner
Greatly influenced by Scandinavian and German culture.
Capital world: Tharkad
The Lyran Commonwealth was considered the Inner Spheres greatest economic power. While as much involved with the Succession Wars as every other state, their focus had historically been on defense and border skirmishes, rather than invasion. The Lyran Commonwealth is frequently contested by the Draconis Combine and the Free Worlds League, which no doubt helped lead to the creation of the Federated Commonwealth in later years, when the Lyran Commonwealth merged with the Federated Suns.
The Lyran Commonwealth is also classically known for inept military commanders, who gain their status through social settings and favors rather than training and skill, often hailing from rich families. This has been known as a crippling factor for the successor state, as their equipment and technology easily outpaced their rivals in the first three succession wars.
 Notable Characters
 House Steiner-Davion
The Federated Commonwealth came into being with the marriage of Hanse Davion and Melissa Steiner, joining the Federated Suns and the Lyran Commonwealth into what was the most powerful of the Successor States.
The union lasted only 20 years, as unrest caused by the Clan invasion and the assassination of Melissa Steiner-Davion enabled Melissa and Hanse's second child Katherine Steiner-Davion to seize much of the former Lyran Commonwealth from her brother, Victor Steiner-Davion's control. Katherine went on to stage a coup against her younger sister, Yvonne Steiner-Davion and took control of the former Federated Suns half of the Commonwealth while Victor was off fighting Clan Smoke Jaguar. This lead to a civil war which raged for five years before Victor's allied forces successfully defeated Katherine and her supporters.
Rather than try to reforge the union of the two nations, Victor opted to aid the healing process by returning both nations to their prior separate constitutions and abdicating as Archon-Prince in favor of his surviving younger siblings; Archon Peter Steiner-Davion and Regent Yvonne Steiner-Davion.
 Notable characters
While not strictly defined as one of the Successor States, ComStar is politically influential, as it maintains a monopoly over the HyperPulse Generators (HPG), 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.
 Notable characters
 Word of Blake
The Word of Blake was once part of ComStar, but splintered from the order due to a difference in beliefs. It was founded by Demona Aziz, the then-Precentor of Atreus. Created after the death of Primus Myndo Waterly and the Battle of Tukayyid that halted the Clan invasion, it at first received support and refuge from the Free Worlds League, who employed them to control their hyperpulse communications network. However, it launched an invasion of Inner Sphere territory, and eventually captured Terra from ComStar in 3058. When the Star League was disbanded in 3067, the Word of Blake launched a jihad against the rest of the Inner Sphere. The opening of the Jihad included an attack by allegedly rogue mercenary units on the Wolf's Dragoons homeworld of Outreach, as well as assaults on Tharkad, New Avalon, Luthien and several other important worlds. The goal of the Word of Blake Jihad was an extension of the original plans of ComStar's founder, Jerome Blake, Operation Silver Shield, to capture some of the Terran Hegemony worlds and hold them under ComStar's control.
However, resistance began to grow when Professor David Lear and the Republic of the Sphere's future founder, Devlin Stone, escaped from a Word of Blake reeducation camp and organized a local resistance movement that destroyed Word of Blake forces on Kittery. Soon, the resistance developed into a widespread organization that was joined by ComStar, the Successor States, the Clans, and the mercenary unit Wolf's Dragoons. Once united, they succeeded in pushing the Word of Blake back, until their final defeat on Terra in 3081.
Common Nicknames: Blakist