BattleTech eras

Catalyst Game Labs, the current owners of BattleTech, have divided history into eras and sub-eras. The products they release are grouped in this manner.^[1]

Era	Sub Era	Years	Description
Pre-Star League	Pre-Spaceflight	Before 1950	Earliest era referenced - when humanity only resides on its planet of origin, Terra.
Pre-Star League	Early Spaceflight	1950 – 2005	Early spaceflight, restricted to the bounds of Sol. Notable events include the Second Cold War and reestablished Soviet Union.
Star League^[2]	Age of War	2005 – 2570^[2]	The age of the Terran Alliance, the fall thereof, the Terran Hegemony and the Ares Conventions. KF Drive tech is proven, beginning the Terran Exoduses in the 22nd century. By the 23rd, unrest sparks the Outer Reaches Rebellion, the Alliance loses, and the Demarcation Declaration invokes the Second Terran Exodus. The first independent interstellar nations are born, the Periphery is settled, and an age of consolidation takes hold over the 24th century. The Alliance would morph into the Hegemony, and many Great Houses are formed. The outbreak of the Age of War itself sweeps the Inner Sphere in 2398. The Ares Conventions would regulate warfare in 2412, and in 2439 the Terran Hegemony would assert dominance by fielding the BattleMech - the Mackie.
Star League^[2]	Star League	2571 – 2780^[2]	The time of the First Star League as established in 2571, to the fall of the Amaris Empire in 2780. The Reunification War is waged, bringing the Periphery in line, and for nearly two centuries humanity is united under a single banner. Advancements in science and engineering backed by the greatest military in history uphold nearly two centuries of peace and prosperity across all settled worlds. Save for chafing such as the First Hidden War, the SLDF would rarely see true conflict until the 28th century, during the Periphery revolts. Then, the Amaris Civil War would bring the end of everything.
Succession Wars ^[3]	Early Succession Wars	2781 – 2900^[3]	The collapse of the Star League is followed a few short years later by the beginning of the Succession Wars - in this timeframe, the First and Second. The Star League is gone; the SLDF vanishes by 2784. Hardly more than half a decade goes by before the First Succession War begins, and nine years pass before the Second Succession War. Billions would die between the two conflicts, and generations of knowledge are blown away in in the nuclear fires set by all involved factions. The Third Succession War begins in the latter half of the 29th century lacking much of what had once been known. ComStar emerges as the last surviving ministry of the Star League, and by the end of the era devolves - or perhaps, evolves - into a pseudo-religious order.
	Late Succession Wars – LosTech	2901 – 3019^[3]	With much of the Star League's knowledge blown away on irradiated winds, the Third Succession War continues. Advanced technologies have been rendered LosTech, and in contrast to the preceding conflicts the Third Succession War is more of a constant low-intensity conflict - one that spans nearly two centuries. Combat grows more ritualized and medieval amongst 'Mechs, and at times duels are fought between MechWarriors for the sake of retaining what still worked. Neo-feudal societies arise, and progress stagnates if not decaying further.
	Late Succession Wars – Renaissance	3020 – 3049^[3]	The Third Succession War ends, the Helm Memory Core is rediscovered, and the contents spread across the Inner Sphere, beginning a techno-industrial renaissance. Repair of ancient 'Mech tech is not just possible, but a reality for the Great House Militaries, and production is restarted and upswings in the start of a resurgence. The ramp-up begins just in time for the marriage of Hanse Davion and Melissa Steiner to begin the Fourth Succession War, and solidify the union of the Lyran Commonwealth and the Federated Suns. The Capellan Confederation is crippled for decades to come, and Wolf's Dragoons are granted the world of Outreach for their service to the Federated Suns. The nascent Federated Commonwealth would continue on to hammer the Draconis Combine in the War of 3039, but the efforts of Theodore Kurita and ComStar would stonewall them into a peace treaty. Nonetheless, the Federated Commonwealth was born, and dominated the Inner Sphere like none since the Star League.
Clan Invasion ^[4]		3050 – 3061^[4]	Coreward of the Inner Sphere, a force struck from the Deep Periphery and carved a path towards Terra. Armed with superior technology, superior genetics, and aggressive tactics, they called themselves the “Clans”. Their unique OmniMech designs and Elemental warriors were unlike anything the Sphere had seen since the Star League Defense Force - and in fact, that was who they once were. Descendants of General Kerensky's exodus forces, the Clan Invasion was a crusade to the heart of the Sphere that was utlimately put on hold by the ComGuard. The Battle of Tukayyid and ensuing truce cost many lives, but bought valuable time. Clan Wolf and Clan Jade Falcon would wage the Refusal War in the intervening years, resulting in a split clan, an exhausted Jade Falcon - and the Battle of Coventry. The Second Star League was born in the aftermath, Operation BULLDOG was fought, Task Force Serpent deployed - and Clan Smoke Jaguar was annihilated. The Great Refusal was then fought and won by the second SLDF, and the Inner Sphere had reestablished a technical knowledge base approximate of the First Star League.
Civil War ^[5]		3062 – 3067^[5]	While the Great Refusal ended the Clan Invasion, the following era would see the Inner Sphere fall on old habits. In the wake of Operation GUERRERO, the Lyran Alliance seceded from the Federated Commonwealth. Formerly supported by the FedCom, the St. Ives Compact was weakened by the fracturing of their allied state. Exploiting the shift in power, First Lord Sun-Tzu Liao would instigate the Xin Sheng Campaign - and it is in GUERRERO, the Alliance, and aborption of St. Ives that the stage is set for the true civil war. Erupting in 3062, the FedCom Civil War theoretically pitted Loyalist Lyran forces against the pro-FedSuns Allies. In practice, it opened to dozens of meat-grinders, fratricidal contests within the same units, battles over worlds once shared, and militiamen with contested loyalties. It defined the entire era, and secondary conflicts such as the Kokuryu-kai-instigated Combine-Dominion War would start and end before it was over.
Jihad ^[6]		3068 – 3080 ^[6]	The time period known as the Jihad refers to a major interstellar war that involved all major factions, mainly consisting of the faction called the Word of Blake attacking capitals and other, important industrial worlds to hamper their enemies' capacity to wage war. They created a "white-out" of the HPG grid that forced regional leaders to take a more active role, then manipulated those leaders to create chaos and warfare that distracted their enemies from the Word's activities. Using "hidden" armies they hit former Chaos March worlds in the vicinity of Terra, which led to the formation of the new state, the Word of Blake Protectorate. The Jihad was not only of the Word of Blake assaulting foreign powers, but also civil conflicts that erupted between states due to the chaos and the actions of the factions.
Dark Age ^[7]	Republic	3081 – 3130 ^[7]	With the Word Of Blake's defeat at the start of this era using coalition forces made possible through unifying efforts of Devlin Stone and David Lear to crush them. The formation of the Republic of the Sphere out of the ashes of the Word of Blake Protectorate created a new buffer state between the various Inner Sphere powers. Additionally the Republic set in motion a plan with the other major factions to decommission BattleMechs and other tools of warfare, downsizing armies and removing any such material from the hands of private individuals.
Dark Age ^[7]	Dark Age	3131 - 3152 ^[7]	The time since the collapse of the HPG network caused political chaos in The Republic of the Sphere that led to the militarization of Industrial Mechs and other civilian equipment. Then the steady advancement of the Great Houses and Clans themselves began to take back worlds they ceded to the Republic, as the fragmented and stumbling Republic made an easy target. Finally ending with the ilClan Trial being fought on Terra, days after the broadcasted disbanding of the Republic.
ilClan^[8]	ilClan	3152 – ???? ^[8]	The once-invulnerable Republic of the Sphere lies in ruins, torn apart by the Great Houses and the Clans. As Fortress Republic collapses, the Clans race toward Terra to create a supreme authority which will rule the Inner Sphere by any means necessary.