Albert

Albert, Prince of Saxe-Coburg and Gotha, more commonly known as Prince Albert, was the husband of Queen Victoria.

Biography
Together with George MacLeish, he created the light chamber, a device to combat the threat of "Werewolves" as dictated by legend. Albert had the Koh-i-Noor fashioned into the optimum shape to best amplify the light of the Moon; this meant that it was constantly being re-cut and once finished, it was half its original size.

Albert widowed Victoria, never seeing the Koh-i-Noor's completion. Victoria missed him greatly and developed a taste for the occult, with the hope of making contact with him. (DW: Tooth and Claw)

Behind the scenes
According to REF: ''Doctor Who: The Encyclopedia, a non-narrative source, Albert died in 1861.