Slyne

Slyne was the Castellan after the Dogma Virus had ravaged Gallifrey. He supported re-electing Romana II to be president. He piggy backed from his original Gallifrey on K9 Mark II and brought the Daleks to this universe. He was the anomaly that the Daleks went to find. After the Matrix doors that they used to were closed by Lady Trey, they exterminated him. (AUDIO: Ascension)

Alternate timeline
In an alternative timeline, Slyne was the Castellan of Gallifrey. He was concerned for Romana's safety and assigned Lukas to guard her. He didn't particularly like Romana. He noticed that she and Narvin were different to what they were before the assassination attempt. (AUDIO: Emanciptaion)

He called Romana away from a science conference for her to meet Kavil. (AUDIO: Evolution) He later led the expedition to Leela's township to get Lord Zakar back from her. After Narvin played the footage of Zacker's orders to commit murder, he arrested Zakar. (AUDIO: Arbitration)

When Romana called the Chancellory Guard, he warned the Daleks of their firepower, and wanted to know who they were. He called them stupid machines and wondered where they came from. The Daleks wanted to keep him them to disrupt the Guards confused. Romana told him the Daleks one weakness, their Eyestalk. He declared war upon the Daleks. He was later exterminated by them. (AUDIO: Extermination)