Neville Plumstead
From Tardis Wiki, the free Doctor Who reference
Neville Plumstead was the chief assistant at the Royal Observatory. He was given the power to absorb future timelines by a creature, allowing him to keep himself young for more than eighty years, during which he served as Astronomer Royal.
In the 1890s, Plumstead showed Jenny Flint and Charlotte Mayfly around the observatory. Vastra realised that he was a puppet and, with her help, Plumstead was able to undo his actions, destroying the creature and killing himself in the process. (AUDIO: The Ghosts of Greenwich)