Aldus was born in 1915 to unidentified parents, later known as Joe and Edith Boardman, reincarnations of Prince Khufu and Priestess Chay-Ara. After hearing them speak of Vandal Savage at night, they decided to tell him of their eternal cycle of reincarnation and their conflict with Vandal Savage. When Aldus was ten years old, Savage once again found his parents. Aldus survived because his mother hid him in a closet and told him to remain silent. The resulting tragedy motivated Aldus to study everything he could about Savage, leading him to become a professor.
On April 8, 1975, Professor recorded himself on a video tape. He displayed knowledge of Hath-Set/Vandal Savage, Khufu and Chay-Ara's origins. He said that his immortality had come as a result of "unearthly calamity" and that anything related to that calamity would possibly reverse its effects. Professor Boardman also expressed his belief that Vandal Savage was the greatest threat Earth would ever face.
According to history, Boardman would later die of unknown causes though possibly at Vandal's hands, which prompted rogue Time Master Rip Hunter to recruit a team and traveled back to October 17, 1975 to acquire information about Savage throughout history from Aldus before his death. At the time they enter his office, Boardman had dozed off and Kendra assumed he had already died. Suddenly, Aldus woke up and was surprised to see the spitting image of his parents, their reincarnations Kendra Saunders and Carter Hall staring right at him, standing in his office. Rip then interrupts him, claiming to be a fellow historian interested in Vandal Savage.
Boardman subsequently went on to explain the origins of Savage's immortality, as well as his own personal history with Khufu and Chay-Ara. He then revealed Savage's meddling over the course of history, starting out conflicts for his eventual world takeover while keeping his anonymity. He then gave Rip a journal detailing all he had discovered about Savage in the hopes that they could stop him once and for all.
Suddenly, Rip got an alert that his timeship, the Waverider, was under attack. Though he was all for preserving the timeline, Kendra and Carter persuaded Rip to bring along Aldus. When they arrived, the timeship was under attack by Chronos. Boardman took cover as Rip's team engaged the temporal bounty hunter, all the while being amazed by Rip's "laser gun". Unfortunately, Aldus was critically injured during the crossfire and thus was brought onboard for medical treatment. With his dying breath, Aldus bequeathed to Kendra his mother's ring.
- "Legends of Yesterday" (video recording)
DC's Legends of Tomorrow
- "Pilot, Part 1"
- "Pilot, Part 2" (mentioned)
- "Left Behind" (mentioned)
- "Progeny" (visions)
- "Leviathan" (mentioned)
- "River of Time" (vision, photo)