After Secret Invasion, Black Bolt, King of the Inhumans, left Earth with his people to fulfill their destiny - lead the Kree Empire. In order to gain the acceptance of the people, a marriage was arranged between Crystal of the Inhumans and Ronan the Accuser of the Kree.
Meanwhile, Majestrix Lilandra of the Shi'ar Empire was overthrown by the insane mutant Vulcan, brother to Cyclops and Havok. Vulcan controlled the Shi'ar with fear and started his campaign to control the universe by attacking the Inhumans and the Kree at the royal wedding.
During the sneak attack, the Imperial Guard of the Shi'ar caused much damage and kidnapped their former leader Lilandra who was on Hala seeking asylum. This attack and insult began the Shi'ar-Kree War, also known as the War of Kings.
Vulcan began using planet killing devices immediately, weapons capable of incredible amounts of death and destruction. In retaliation, the Inhumans sent their new weapons - the Chorus Sentry - and destroyed entire fleets of Shi'ar vessels. In the meantime, the Inhumans devised a plan to have the Starjammers rescue Lilandra and have her take back control of the Shi'ar from Vulcan in order to limit the amount of bloodshed and end the war early.
The Starjammers were assisted by the Guardians of the Galaxy and luckily for them, Gladiator changed his loyalties back to Lilandra. They all returned to Chandilar to secure her rightful place at the throne of the Empire. But Vulcan had the assistance of Talon of the Fraternity of Raptors who assassinated Lilandra. This caused riots and a civil war among the Shi'ar.
With their plans failed, the Inhumans launched their contingency plan - a device known as the T-Bomb that would expose the Shi'ar to the Terrigen Mists and thus make them Inhumans as well. Black Bolt hoped that this would stop the war since they would be the same and not have differences that cause wars. What Queen Medusa did not know what that this required Black Bolt's sacrifice.
Against the wishes of Crystal and Ronan, the bomb was launched. It was intercepted by Vulcan, and the War of the Kings took place aboard the ship. It seemed that Black Bolt had killed Vulcan when Crystal arrived a deactivated the Terrigen Mists, but this still left the device as a massive ordinary bomb. She was about to rescue Black Bolt when Vulcan attacked, surviving Black Bolt's attack.
The device exploded, killing Black Bolt and Vulcan. The Shi'ar surrendered unconditionally, leaving the Inhumans in command of both the Kree and Shi'ar Empires with Medusa as queen.
The explosion of the T-Bomb ripped a massive hole in space-time known as the Fault. This would begin the Realm of Kings story arc.