The First Succession War lasted from 2787 to 2821, a conflagration of unparalleled brutality. The warring Lords of the five Great Houses cast aside the Ares Conventions, smashing cities, destroying vital industrial facilities, and butchering hundreds of millions of civilians. Few worlds escaped unscathed, and all were affected by the complete disruption of trade, commerce, and communications. By 2815, the warring states had lost most of their FTL shipbuilding capacity. The intense concentration of economic resources into military production had also forced a major drop in consumer goods production, creating a severe decline in trade. This loss of trade proved particularly disastrous for those worlds relying on high-tech water purification equipment. Without proper maintenance or spare parts, many of these facilities began to fail, forcing abandonment of the worlds or a return to iceship technologies. By the war's end in 2821, water-rich planets had become as strategically valuable as they had been 400 years before.

The peace of 2821 was uneasy, resulting more from exhaustion than any true reconciliation. Though no House Lord could claim to have made much progress toward his goal of dominion, too many atrocities had occurred to allow any sort of lasting settlement. From 2821 through 2827, the five surviving ruling Houses rebuilt as much of their military might as possible, concentrating their surviving scientists and engineers on those few worlds whose industrial capacity remained intact. Between 2828 and 2830, tensions along the borders of each rival state erupted, leading once more to all-out war.

The Second Succession War lasted from approximately 2830 to 2864, and was just as deadly, destructive, and indecisive as its predecessor. Hundreds of millions more died in countless battles across the Inner Sphere, though only a few dozen worlds ultimately changed hands. As the war destroyed more industrial facilities and killed off more scientists and engineers, some types of specialized knowledge and technology began to disappear entirely. By the end of the Second Succession War, what had become known as the Successor States' overall level of technological knowledge sunk to a level barely above that of Terra in the early 21st century. It was no longer easy to build advanced computers, large fusion power plants, or starships. Instead, the leaders of the Successor Houses began to cannibalize existing equipment for the spare parts necessary to keep their current war machines in working order.

After a second brief respite, the Third Succession War erupted in 2866. It began when advance forces of the Draconis Combine invaded the coreward portion of the Lyran Commonwealth; war soon spread across the Inner Sphere. In the years that followed, combat became such a fact of everyday life that the period become known simply as "the Succession Wars." Nonetheless, campaigns during this period never matched the violence of previous two wars.

At first, the decrease in destruction and bloodshed appeared to be more a function of each army's reduced resources than philosophical change in tactics. As time passed, however, and the exigencies of a scavenger economy took hold, each of the Houses realized it could ill afford further losses of vital resources. Gradually, an informal set of rules of war evolved, similar to the Ares Conventions. 'Mech units and armies still fought over possession of operational factories, but neither side attempted to harm the facility itself. (The losers simply consoled themselves with the idea that they would win the planet in the next war). Major 'Mech battles, especially between mercenary units, were often fought in stages, with both sides allowing enemy Techs to enter the battlefield during periods of truce to attend to damaged 'Mechs. Other 'Mech units, again especially mercenaries, revived the old tradition of surrendering to a superior force and paying a ransom to obtain their off-world release. Most important, everyone recognized the sanctity of any side's JumpShips, and strictly obeyed the prohibition against attacking such craft. After all, without JumpShips, the war for supremacy could not be waged at all.

A second outgrowth of the destructiveness of the Succession Wars was the rise of feudalism throughout the Inner Sphere. The central governments of the ruling Houses no longer possessed either the administrative machinery or absolute military resources to maintain centralized control over their territories. Instead, each House Lord ruled a hierarchy of planetary nobles. These nobles were often drawn from the leadership of his most elite 'Mech units, having won full authority over worlds in exchange for the pledged service of their BattleMechs.

Indeed, the years of conflict wreaked havoc beyond the borders of the Successor States, creating the phenomenon known as the Bandit Kings of the Periphery. As the wars raged back and forth along the frontier, dozens of 'Mech units - most often composed either the fragments of defeated units or mutinous mercenaries - fled into the vastness of the Periphery. Several of the units emerged again, often after a number of years, as "kings" of one or more small worlds seized by force of arms. By the end of the 30th century, more than 60 known small kingdoms and principalities ringed the Inner Sphere, creating the ever-present threat of raids and piracy to the frontier worlds of each Successor State.

This era of tentative stability lasted for roughly a century. Interestingly, it was a call for lasting peace that marked the end of a relative balance of power among the Great Houses and began the ferocity of the Fourth Succession War.

Recognizing humanity's slow but steady slide away from the glories of the Star League era and toward barbarism, Archon Katrina Steiner of the Lyran Commonwealth issued a Peace Proposal to the other House leaders in 3020. Only Hanse Davion, Prince of the Federated Suns, welcomed the initiative. Announcing that he would "take history by the throat," Davion began negotiations with the Archon. The result of these talks was the Federated-Commonwealth Alliance Document, which Prince Hanse Davion and Archon Katrina Steiner signed on Terra in 3022. In addition to trade and military agreements, the F-C Document contained a secret provision betrothing the Archon's daughter in marriage to Hanse Davion. Though the marriage would not occur until the twelve-year-old Melissa came of age, this was the first step on the road to eventual unification of the Lyran Commonwealth and the Federated Suns.

The other three Successor Lords were aghast at this sudden shift of power, which would lead to the eventual creation of a single state nearly as large as their three Houses combined. In October 3022, the Draconis Combine, the Free Worlds League, and the Capellan Confederation hastily signed the Concord of Kapteyn. The scope of the Concord was not as far-reaching as the F-C Document, however. It called mainly for an end to active hostilities between the three states, who now pledged mutual defense instead. This new relationship would also permit the three parties to coordinate their overt and covert efforts at derailing the Davion-Steiner alliance.

Perhaps most active in the covert attempts was the Capellan Confederation under the leadership of Chancellor Maximilian Liao. Liao agents had already subverted Hanse Davion's brother-in-law Michael Hasek-Davion, who was now providing them with valuable military intelligence. When the Chancellor next initiated a scheme to kidnap and kill Hanse Davion in order to replace him with a clone his scientists had created, he went too far. Davion eventually escaped capture and imprisonment and returned to his place on the throne. But he vowed revenge.