Pandak was one of the six founders of Time Lord society. (PROSE: The Ancestor Cell) He was the President of Gallifrey, (AUDIO: Babblesphere) during the Time Lord's Eternal War with the Great Vampires. (PROSE: The Scrolls of Rassilon)
Rassilon overthrew him in a coup and took Gallifrey for himself. Pandak was imprisoned with the rest of the High Council. Pandak was released after he agreed to resign from office. (PROSE: The Scrolls of Rassilon)
One of his titles was "Pandak the Original", because of the numerous Presidents after him also named Pandak. The currency on Gallifrey was named after him. (PROSE: Lungbarrow) One of his relics was Pandak's staff. (PROSE: Divided Loyalties)
Behind the scenes
One of the digital currencies used for the video game Doctor Who: Worlds Apart are called Pandaks and are named after Lord President Pandak.