Kotan Pa'Dar was a high ranking Cardassian politician in the 24th century. He was at one time married to a woman with whom he had a son, Rugal. Among his political relationships, he had Gul Dukat as a rival.
During the Occupation of Bajor, Pa'Dar was an Exarch in a Cardassian settlement on Bajor. In 2362, he believed his wife and son were killed by Bajoran Resistance fighting to free their world from the Cardassian Union.
Pa'Dar was part of the decision to end the Occupation and evacuate Bajor in 2369. He met resistance, including with Gul Dukat, who lost his position as Prefect as a result. They would remain rivals afterward.
In 2370, after the exposure of the Cardassians' involvement in the coup executed by the Bajoran Alliance for Global Unity, Pa'Dar was put in charge of the investigation to investigate and prosecute the high-ranking officers involved. Dukat was one of those suspected.
Later that year, it was learned that his son, Rugal, had survived the attack in 2362 and was being raised by a Bajoran family, as the boy was thought to be an orphan. Pa'Dar and the government were informed about Rugal's existence, and Pa'Dar immediately traveled to Deep Space 9, anxious to reunite. Dukat planned to use this evidence in an attempt to politically disgrace Pa'Dar. Dukat's plan was foiled when Elim Garak and Julian Bashir found out that Rugal was deliberately left behind by Dukat. Sisko then returned the boy to his father and they returned to Cardassia. (DS9: "Cardassians")