The Champions of Xandar were originally known as The New Champions and named by Nova (Rich Rider) in order to defend Xandar from the Skrull Invasion. The New Champions consisted of Protector , Nova Prime, the Comet, Crimebuster, Powerhouse and Diamondhead. However, Diamondhead and Crimebuster only served briefly since the former defected to the Skrulls while the latter was killed in the ensuing struggle. It was at the hand of Rom that they were saved from another dimension that Diamondhead activated as a trap during his betrayal. After the rescue, the Champions and Nova Corps drove out the remnants of Skrulls from their homeworld.
The Champions of Xandar where created by Marv Wolfman and John Buscema and first appeared in Fantastic Four Vol.1 issue 208 (1979).
Major Story Arcs
The team was formed by Nova's foe, the Sphinx, as part of a scheme to reach Xandar. After stopping the Sphinx, the team stayed together to fight in the Xandarian/Skrull War. The New Champions stayed together for almost a year and pushed back the Skrull forces with the assistance of Rom. After the war, Rich Rider chose to relinquish his Nova powers in order to return to Earth. Nova's position in the team was filled by his successor, Centurion Nova Prime : Tanak Valt.
Unfortunately, the team suffered their first crisis when Diamondhead betrayed the team to the Skrulls and caused the death of Crimebuster. As the team and entire Nova Corps were trapped in another dimension, they were unable to assist their home's defense until Rom and Nova rescued all of them. Though the team remained intact and Skrulls were driven off, the team suffered both their first betrayal and first casualty.
After Rich Rider returned to Earth, the rest of the team stayed on the Xandarian homeworld and renamed themselves the Champions of Xandar. All of the Champions were killed during Nebula's destruction of Xandar.
Years later a fail-safe plan (created by Protector and Queen Adora ) reactivated Xandar`s computerized Worldmind which resurrected the Xandarians in cloned bodies. The Nova Corps became the Xandarian Star Corps and Nova fought with them occasionally. Only the Protector was only one revived albeit as a fragment of his personality imprinted into the computer as Tanak and possibly other members weren't cloned according to Adora's lament of her present mire in politics in Volume, Issue 17 of Nova comic.