Timeline

2001-2100: Breakthrough
2011	Second Soviet Civil War
2014	End of Soviet Civil War as combined American and Western European troops intervene to end hostilities.
2020	Development of Fusion power: first fusion reactor. Thomas Kearny and Takayoshi Fuchida release their initial findings on physics and are ridiculed.
2024	Formation of Western Alliance It is composed of forces involved in the war, it includes Japan, Eastern European nations recently liberated, and the now separate seven Russian States. The Alliance begins vigorous support of scientific and space exploration efforts.
2027	The Alliance starship Columbia, power by the first Kearny-Fuchida fusion engine, made its history journey from Earth (Terra) to Mars in 14 days. Myomer fiber research begins.
2047	Thomas Kearny dies.
2050	The Alliance has established scientific outposts throughout the solar system. Private corporations begin establishing commercial colonies in space, resulting in research for better materials and smaller portable fusion reactors. Long range space probes launched to nearby stars. Several habitable worlds are discovered.
2086	Formation of the Terran Alliance. The Alliance expanded to 120 member-states. The Alliance Parliament replaces weak United Nations.

2102-2313: Exodus
2102	Faster Than Light (FTL) stardrives developed based on Kearny/Fuchida research. The JumpShip is invented but the cost of the project causes civil unrest.
2108	On December 5, maiden voyage of an interstellar ship, TAS Pathfinder, to Tau Alpha Ceti.
2116	First colony established on Tau Alpha Ceti IV (New Earth), following the commercial production of FTL spacecraft.
2172	Over 100 settled worlds in a 80 light years radius.
2177	Rudolph Ryan invents the Iceship to solve water shortage problems.
2213	New Avalon settled by colonists composed largely of English, Scottish, Irish, German, and Scandinavian people.
2235	More than 600 worlds settled scattered across a sphere roughly 80 light years in diamater.
2236	A group of colonies declares its independence, starting with Denebola. After an 18 month war it is clear that the Terran government lacks the resources necessary to crush the rebellion.
2242	Terran government grants independence to all of its colony worlds. Soon the boundary of Terran space shrinks to a 30 light year radius. People begin migrating to escape the unrest on Earth.
2250	Rim Worlds Rim Worlds Republic formed.
2253	Taurus colonized, Taurian Concordat formed.
2271	Formation of the Free Worlds League. The first of many associations of colonies to be formed as Terra began to lose touch and control of its colonies.
2312	Over 1500 settlements in a 150 light year radius from Terra.

2314-2398 Consolidation
2314	Collapse of the Terran Alliance due to Civil war on Terra. Warfare broke out between Liberal and Expansionist parties on Terra. Admiral James McKenna intervened with Alliance Military Forces and halted the conflict.
2315	Creation of the Terran Hegemony. A resurgent Terra under Admiral McKenna managed to regain control over 100 former colonies.
2317	Formation of the Federated Suns with the Crucis Pact. Soon after, several mutual defense leagues similar to the Treaty of Marik begin to take shape.
2319	Formation of the Draconis Combine by Shito Kurita after a brutal military campaign.
2339	McKenna Dies.
2340	Michael Cameron is elected to replace McKenna as Director-Generalship of the Terran Hegemony. During is term in office, The WorkMech is invented using Myomer technology refined by Dr. Gregory Atlas.
2341	Michael Cameron recognize the Lyran Commonwealth (January 5, 2341).
2351	Michael Cameron took an action whose cultural repercussions would echo for centuries. He created the Peer List, establishing the equivalent of a feudal nobility whose members owed their exalted rank to their achievements.That list eventually led to the creation of feudal ruling families in the various independent states surrounding the Hegemony.
2367	On July of that year, official birth of the Capellan Confederation.
2389	The formation of the Inner Sphere and the Periphery. Ten strong, centralized states emerged to rule over the "Human" sphere: Inner Sphere Draconis Combine Federated Suns Lyran Commonwealth Free Worlds League Capellan Confederation Terran Hegemony Periphery Magistracy of Canopus Outworlds Alliance Taurian Concordant Rim Worlds Alliance

2398-2550 Age of War
2398	The Age of War begins as forces of the Capellan Confederation and the Free Worlds League clash in the Andurien system. A number of short, bloody conflicts follow throughout the Inner Sphere and the Periphery.
2412	Ares Convention signed. After the battle of Tintavel results in thousands of civilian casualties, representatives of the states meet to formulate and sign the Ares Convention, a set of rules for warfare and and a way to minimize civilian casualities. The Ares Convention was written and signed by all of the Inner Sphere states, but by only 2 Periphery states. Though the Ares Convention reduce the damages of war, they also cement war as a way of life, and a method of settling even the smallest disputes.
2439	On February 5, the BattleMech invented (Mackie MCK-5S), creating a vehicle with greater mobility and firepower than previous vehicles.
2449	First BattleMechs deployed by cargo carrier.
2453	First BattleMechs deployed by combat drop.
2455	Lyran Commonwealth raid on Hegemony mech production facility on Hesperus II (February 7, 2455). Battlemech technology begins to spread throughout the various states.
2459	First use BattleMechs in combat.
2449	First DropShip used.
2550	The Age of War ends in another battle between Houses Marik and Liao over Andurien.

2551-2600 Imperium and Reunification
2571	Formation of the Star League. Ian Cameron become First Lord, with the rulers of the Inner Sphere holding seats on the High Council.
2578	With the Taurian Concordat, The Rim Worlds Republic, and the Magistracy of Canopus resisting all efforts to be brought into the League by diplomatic means, war is declares between the Star League and the Periphery States. Reunification War begins.
2597	Reunification completed, the Periphery States surrender, becoming territories ruled by the Star League. The Reunification War claimed more casualties then the entire Age of War.

2601-2750 The Good Years (Longest period of peace in recorded Human history)
2602	Ian Cameron Dies. His son Nicholas is named First Lord.
2615	Development of the HyperPulse Generators (HPG), permitting FTL communication. The first message was sent in 2630 into the Lyran Commonwealth. In following years the Star League Establishes a network of stations tying the many systems of the Star League together efficiently for the first time. At the same time, a cheap water purification system is invented, rendering IceShips obsolete.
2646	Nicholas Cameron named his grandson Michael Cameron as successor.
2649	Nicholas Cameron dies. Michael Cameron is now First Lord.
2650	When intelligence reports indicate that the Rim Worlds are building their army at an alarming rate, Michael Cameron and the Council issue an edict limiting the size of private forces in the states. Though obvious buildups are halted, secret armies are built and small wars occasionally fought despite the apparent unity of the Star League.
2690	Cameron retires as First Lord, his son Jonathan Cameron is designated as his successor.
2638	Jonathan Cameron dies of a stroke. His son Simon Cameron take the seat.
2750	Over a thousand new worlds were colonized, expanding Human inhabited space to roughly 540 light years in diameter.

2751-2784 Crisis and Civil War
2751	Death of Simon Cameron (February) First Lord of the Star League, Simon Cameron, was accidentally killed, leaving his eight year old son, Richard, heir. General Aleksandr Kerensky is appointed Regent and Protector.
2751-2761	Regency The 2650 edict of Micheal Cameron is cancelled. The Council Lords, consisting of the leaders of the great Inner Sphere Houses, increase their armies. They pay for this spending by increasing taxes on the Periphery
2762	First Lord Cameron reaches his Majority, and issues an order to disband all independent armies. His proposal is struck down. In response, he dissolves the council, vowing to rule by decree.
2763	Richard Cameron's tax edict rejected by the periphery. Kerensky sent to cow the revolt brewing there.
2764	Stefan Amaris signs secret pact with Richard to protect Terra. When Cameron House units are sent to the Periphery as well, Amaris forces are the only ones left to guard Terra.
2765-2766	Secession 17 Periphery worlds secede from the Star League. The Star League Regular Army is deployed to fight the secessionists.
2766	On December 27, Stephan Amaris kills Richard Cameron and every man, woman and child with a drop of Cameron blood. At the same time, his troops move against Terra and other planets of the Terran Hegemony. Amaris declares himself First Lord of the Star League.
2767	Kerensky declares cease fire with all Periphery States except the Rim Worlds and declares full war with the Usurper (Stephen Amaris) and his realms. He takes the Rim Worlds Republic, then returns to the Terran Hegemony.
2779	After a long campaign,Kerensky liberates Terra, and executes the Usurper and his entire family in retribution for his actions. Of the original 486 divisions of the Star League Regular Army, only 113 still exist. Kerensky proclaims himself Protector of the Realm and invites the Star League Council to reconvene on Terra. Jerome Blake appointed minister of communications and placed in charge of repairing the Star League Communications network.
2780	The council lords convene and stripped General Kerensky of his tittle as Protector of the realm, and ordered him to disperse all SLDF units to their peacetime locations.
2781	In August, the Council Lords fail to choose a new First Lord and dissolve the Star League. Each lord then begin to built his own power base.
2784	Operation Exodus On February 14, Kerensky proposed to his troops that the SLDF should leave the Inner Sphere and found a new society. On November 5^th, he and 80% of the SDLF leave the Star League Territory and pass beyond the Periphery. The remainder of the SDLF pledge assistance to the Terran reconstruction effort. Formation of the Iron Brigade (no known exact date)

2786-3030: The Succession Wars
2786	Starting with Minoru Kurita, the Lords of the Inner Sphere each declare themselves First Lord of the Star League. Pentagon Worlds settled by Kerensky's followers.
2787	The First Succession begins. The Major States are The Draconis Combine ruled by House Kurita, The Free Worlds League ruled by House Marik, the Federated Suns ruled by House Davion, The Capellan Confederation led by House Liao, and the Lyran Commonwealth led by House Steiner. Gerome Blake obtains agreements that the Lords of the Inner Sphere will not attempt to damage the communications network. Communications Authority arises as a neutral power in control of the communications network, in the hopes of saving it and the rapidly disappearing technologies of the Star League. The Ares Convention cast aside in a brutal war. Facilities for producing Technology and knowledge of how to produce them are destroyed at an alarming rate. After such a brutal war a lasting peace is neither expected nor wanted. Instead, the short peace is used to build for the next great war. Because of losses of trade for spare parts for purification equipment, many worlds are abandoned, and water-rich worlds become extremely valuable strategic targets.
2788	In the chaos of the war, Jerome Blake captures Terra with mercenary troops in Operation Silver Shield. In reality, the soldiers are SLDF troops who choose not to accompany the Exodus. Jerome Blake declares Terra a neutral world under protection of the Communications Authority. The organization soon takes the name Comstar.
2796	The Kentares Massacre: Minoru Kurita is killed by a sniper on Kentares IV. Jinjiro Kurita orders his troops to kill all the population on Kentares IV.
2801	Aleksandr Kerensky dies. Nicholas Kerensky leads second Exodus with 800 loyal followers Exodus Civil War begins.
2808	Comstar becomes an institute for the preservation of Technology and Knowledge, so that it may reveal it to the people of the Inner Sphere when the fighting is over. Unfortunately, in an effort to prevent this preserved technology from adding further years to the conflicts, measures are taken to maintain a monopoly on Star League technical data. This eventually is perverted into an organization which uses its technology in an attempt to dominate the Inner Sphere.
2810	Nicholas Kerensky founds the Clans.
2811	ROM, the intelligence directorate of Comstar, is formed to prevent the spread of technology and defection of Comstar personnel.
2815	Nicholas Kerensky proclaims himself first ilKhan of the Clans.
2819	Jerome Blake dies on May 15. He is replaced by Conrad Toyama. Toyama initiates the reorganization that will turn Comstar into a religious organization bent on the isolation of Comstar's knowledge and power until the rest of society collapses, at which point Comstar will return to save the human race. Nicholas Kerensky begins the Clan eugenics program.
2821	End of the First Succession War. Clans return to Pentagon Worlds, Exodus Civil Wars end.
2823	Clan Wolverine declares independence fron the Clans. The Wolverines are Annihilated after using a nuclear device to destroy a genetic repository.
2825	The Minnesota Tribe attacks Svelvik, Jarrett, Richmond, and Trondheim (4 Draconis Combine worlds).
2828	The Second Succession War begins. As destructive as the last war, it accelerates the process of technological decline. By the end of the war, technology has sunk overall to 21st century levels, with the great Houses just barely maintaining the technology to fight the war. Though BattleMechs are still built, they can be produced only in small numbers, and spare parts become scarce, as do people capable of doing the repairs. Repair and supply bases become as valuable as water if not more.
2834	Nicholas Kerensky killed. Clan Wolf absorbs Clan Widowmaker.
2837-2838	Free Worlds League interdicted by Comstar after the destruction of the HPG facility on Oriente.
2850	LCAF agent Snow Fire assassinates Combine Coordinator Yoguchi Kurita.
2854	By the time Karpov becomes Primus of Comstar, Comstar has begun subtle manipulations of the Inner Sphere, in order to facilitate Comstar's eventual success. To further aid this effort, he opens a number of positions in Comstar to members of Great House and MechWarrior Families, allowing them access to information on events and what little technological innovation was occurring. Clan Coyote develops the OmniMech.
2864	End of the Second Succession War.
2866	Third Succession War The drastic reduction of resources made the Third a relatively limited war compared to the First and the Second. Unwritten rules similar to the Ares conventions are put into force by the warriors themselves, causing much less destruction and slowing, but not stopping, Mankind's slide into barbarism.
2868	Clans first use elementals. Absorption of Clan Mongoose by the Smoke Jaguars. (note: More Annihilation since none of the Mongoose genetics materials were ever used)
2905	Start of the 25-year cease-fire between the Federated Suns and the Capellan Confederation.
2933	Formation of the ComStar Guard and Militia, later known as the Com Guard.
2959	Creation of the Explorer Service (later known as Explorer Corps) by Primus Adrienne Sims. This division of Comstar will be responsible for charting far distant Periphery worlds.
2985	Clan Sea Fox becomes Clan Diamond Shark.
3005	The Wolf's Dragoons enter the Inner Sphere. They begin to take work as mercenaries with each of the Successors States. They become known as a top line Mercenary Unit.
3010	Morgan and Patrick Kell form their mercenary company, the Kell Hounds
3015	Hanse Davion sets up the New Avalon Institute of Science (NAIS), as a semi-military academy and research center for old and new technologies.
3022	End of the Third Succession War. House Davion and house Steiner sign the Federated Commonwealth Treaty, creating an alliance between the two houses, and betrothing Archon-Designate Mellisa Steiner to Hanse Davion to unite the two kingdoms. In response, the other three houses form their own alliance in the Concord of Kapteyn. Several attempts are made on Davion's life.
3025	Agents of House Liao attempt to replace Hanse Davion with a cloned replacement. Hanse vows revenge.
3026	On the planet Helm the mercenary unit, The Grey Death Legion, recovers a Star League Memory Core.
3028	The Wolf's Dragoon leave Draconis Combine for the Federated Suns. On August 20, wedding of Hanse Davion and Melissa Steiner (Heir Designate of the Lyran Commonwealth). As a wedding gift, Hanse offer the Capellan Confederation. Start of the 4^th Succession War. Lyran Commonwealth attack the Draconis Combine.
3029	St-Yves Compact formed. Tikonov Free Republic formed. Michael Hasek-Davion killed. Federated Suns interdicted by ComStar for an alleged attack on a Comstar station. Later that year, Comstar removes communications interdiction imposed on House Davion . In exchange, Comstar gains the right to garrison its facilities with its own Battlemech troops, gaining 50 regiments by 3050. Precentor Myndo Waterly becomes Primus. She begins taking a more active role in the affairs of the Inner Sphere.
3030	End of the 4^thSuccession War. The Federated Commonwealth declare victory and a cease fire, ending the war.The briefest of all of the Succession Wars, it was a bloody conflict with more worlds changing hands since the First. Draconis Combine receives Star League BattleMechs from ComStar. Duchy of Andurien secedes from Free World League.

3031-3048: Prosperity
3031	Tikonov Free Republic absorbed by the Federated Suns. Thomas Marik leaves ComStar. Capellan Confederation attacked by Andurien/Canopus alliance.
3034	On March 13, Draconis Combine recognizes the Free Rasalhague Republic. Ronin War takes place (Draconis Combine).
3036	Maximillian Liao, having gone mad during the war, kills himself. Romano Liao takes the throne.
3037	Duchy of Andurien retaken by the Free World League.
3039	The War of 3039 begins. The Federated Suns and the Lyran Commonwealth launch an attack against the Draconis Combine. But the Combine, newly outfitted with Star League Era 'Mechs by Comstar pushed back the attack.
3040	The War of 3039 ends.
3041	Armed Forces of the Federated Commonwealth created.

3049-3061: The Clans
3049	On August 13, the Clans invade the Periphery.
3050	In March, the Clans begin invasion of the Inner Sphere.
3052	In January, the Battle of Luthien. In May, the Battle of Tukayyid. Comstar fight the Clans and win a 15 years truce. A schism within Comstar lead to the creation of the Word of Blake due to Comstar releasing Lost Technologies to the Inner Sphere. WoB now control the HPG facilities in the Free World League.
3054	Creation of a new mercenary unit: The Black Thorns.
3056	Federated Commonwealth officially formed.
3057	The Federated Commonwealth lose almost all the worlds taken during the 4th Succession War from Liao and Marik which lead to the creation of the Chaos March. Lyran Alliance formed with Katerina Steiner as Archon (Victor Steiner-Davion's sister) when the Lyran side secede from the Federated Commonwealth. Trial of Refusal between the Jade Falcon and the Wolf. Natasha Kerensky dies on Twycross (December 7^th). Creation of the Arc-Royal Defensive Cordon (Forces composed of the Kell Hounds, Clan Wolf (Warden), and Wolf's Dragoons).
3058	Thomas Marik discovered to be a double. Invasion of Coventry. In early March, the Word of Blake take control of Terra. The Whitting Conference: the conference was held on Tharkad between October 1^st and November 21^st. Sun-Tzu (Liao's Chancellor) was elected First Lord of the New Star League for the next 3 years. Victor Davion would lead the Star League Defense Force (composed of units from all the Successor States and the Wolf's in exile) to strike at the Smoke Jaguar Clan.
3059	The War against the Smoke Jaguar begins. It is a 2 phase attack, the first one, Operation Bulldog, led by Victor Davion, will hunt down the Smoke Jaguar in the Occupation Zone, while the other, Task Force Serpent, lead by Morgan Hasek-Davion, will bring war to the Smoke Jaguar Homeworld, Huntress. Absorption of Clan Burrock by Clan Star Adder.
3060	Assassination of Morgan Hasek-Davion. General Ariana Winston, Eridani Light Horse commander, is now in charge of Task Force Serpent. On February, the invasion by Task Force Serpent of Huntress begins. In April of that year, the Task Force Serpent finished the conquest of Huntress Later that same month, the SLDF, win on Strana Mechty, a Trial of Refusal over the conquest of the Inner Sphere, which binds all the Clans except Clan Wolf and Clan Jade Falcon. The Smoke Jaguars are no more. On April 25th, the SLDF began the long trek back to the Inner Sphere. Clan Ghost Bear relocated most of their assets and people to their Inner Sphere occupation zone, now called the Ghost Bear Dominion. Clan Nova Cat joined the SLDF. The Clan Steel Viper left the Inner Sphere, after challenging the Jade Falcon for dominance of their shared occupation zone. The Steel Viper failed miserably and left the Inner Sphere rather than be destroyed by the Jade Falcon. After a stage Trials of Possessions between the Hell's Horses and the Wolf, the Hell's Horses took possession of 3 planets in the Wolf Occupation zone bordering the Ghost Bear Dominion
3061	Katrina Steiner take control of the Federated Suns portion of the Federated Commonwealth. The SLDF finally arrived on Luthien on March 15^th. In the Second Whitting Conference, on November 5^th Comstar Precentor Martial Anastasius Focht resigns his position. Victor Steiner-Davion becomes the new Martial Precentor of Comstar and also the commander of the SLDF. Theodore Kurita becomes the second First Lord for the New Star League for the next 3 years.

Sources: FASA Sourcebooks, fans websites, BattleTech Novels.