Kindun was the ruler of his namesake planet, he shared some kind of connection with it he considered himself and the planet one. When he was a child, Thanos the Mad Titan and his daughter Gamora tried to conquer it but failed.
Decades later, Kindun hired Nebula and the Chitauri to hunt down Gamora and bring her to him. However, as soon as she was delivered, her teammates, the Guardians of the Galaxy, and the Avengers arrived to rescue her.
Kindun tried once again to have revenge on Gamora by moving the planet to her base of operations at the time, Spartax. Countless troops of Chitauri descended to Spartax and attacked it. When Gamora arrived to Kindun, she was ambushed, but survived the attack due to her recent power acquisition. She tried to convince Kindun to stop trying to kill her, due to the actions of Thanos not being connected to her own. However, Kidun still tried to murder her. In the end, she forced Kindun to retreat.