Salonu Prime was the leader of the Salonu. He was enslaved to the Master's TARDIS and informed the Decayed Master of the Fourth Doctor's habits. It wanted to destroy the humans' economy. (AUDIO: The Evil One)
They came to Earth in 6th century BC to refuel, where their ship was shot down by Cuthbert. (AUDIO: The Pursuit of History) They wouldn't listen to K9 Mark II's warning to stop the nitrogen conversion. (AUDIO: Casualties of Time)