Pandad IV

The President was the Lord President of Gallifrey. Chancellor Goth expected to succeed him, but he informed him he would choose someone else. On Presidential Resignation Day, Goth and the Master assassinated him before he could make his announcement. (DW: The Deadly Assassin)

Behind the scenes

 * Given the average reign of a Time Lord President lasts a few centuries, it seems likely that this was the same President who had been challanged by Omega a few years earlier, possibly having regenerated.