Ronan was a radical Kree warlord and former member of the Accusers. A participant in the Kree-Skrull War, Ronan worked with Yon-Rogg and the Starforce after the Ambush in Torfa to wipe out the last of the Skrull refugees. Ronan and the Accusers were then called to drop warheads on Earth to wipe out the remaining Skrull opposition there but were repelled when Captain Marvel came to Earth's defense. The Accusers retreated, with Ronan promising retribution.
Further disgusted by an armistice made between the Kree and Nova Empires to end the Kree-Nova War, Ronan initiated a new campaign to eradicate the Xandarians by forging an alliance with Thanos, offering the Orb in exchange for the destruction of Xandar. After a long search, Ronan acquired the Orb, but after realizing it had housed the Power Stone, he instead betrayed Thanos and chose to take the Orb's power for himself. Using his newfound power, he and his forces attacked Xandar, only to be defeated and killed by the Guardians of the Galaxy.
In a flashback, when Rick and Tinsel first met the Guardians, they described the battles back in 2014 against Ronan, even how they were chasing after him in the Andromeda Galaxy and recruited Yondu and the Ravagers to save Xandar and the Nova Corp. Star-Lord distracted him to a dance-off before the other Guardians, after old Groot's sacrifice, absorbed the Power Orb and refracted it back incinerating the Kree!
