A man-at-arms of Dragonstone when the Dance began, named the White for his pale hair. He had the look of Valyria on him and dragon's blood enough to prove it, but which Targaryen he sprang from was never set down, and it may be that Ulf himself did not know. He could not read or write, and he drank. When Prince Jacaerys Velaryon called for dragonseeds in 129 AC, Ulf claimed Silverwing, once Good Queen Alysanne's mount, and flew her beside Hugh Hammer, Nettles, and Addam Velaryon at the Battle of the Gullet, where Jacaerys fell. Afterward he began calling himself Ulf White. Prince Daemon would have married him to the late Lord Stokeworth's daughter and later proposed giving him Storm's End; Queen Rhaenyra refused both and settled for knighting him and granting him lands on Driftmark. Mushroom has him riding drunk through Flea Bottom wearing nothing but a pair of golden spurs. "Fie on that," he told Hugh when Hugh said the knighthood had made them true knights at last, "we should be lords."
Sent with Hugh in 130 AC to hold Tumbleton against Lord Ormund Hightower, the two of them turned their dragons on the black host in the middle of the First Battle of Tumbleton and were called the Two Betrayers ever after. Prince Daeron named him Lord of Bitterbridge for the treason, which Ulf thought too small a thing; he wanted Highgarden. He took the Bawdy Badger for his inn and, if Mushroom is to be believed, three maidens a night, and fed those who displeased him to Silverwing. Lord Unwin Peake had the Caltrops' execution warrants drawn and signed by Prince Daeron, but the Second Battle of Tumbleton came first, and Ulf slept drunk through all of it and every attempt to wake him. Learning that Hugh was dead, he informed Lord Peake that he would be taking the Iron Throne. The next day Ser Hobert Hightower brought him two casks, a Dornish red and an Arbor gold, knowing which vintage he preferred and which one he had poisoned. Ulf, suspicious, set the red aside and would not touch the gold until Hobert drank of it first. Hobert drank, and asked for a second cup, and Ulf drank three, and fell asleep, and died in his sleep well pleased.