Charles Babbage

Charles Babbage was an inventor. He built the difference engine in the Victorian era. (AUDIO: Children of Steel, The Similarity Engine; TV: Spyfall)

Biography
Some time before his meeting with the Thirteenth Doctor in 1834, the Silver Lady was delivered to him by a young man, who said it was a token of appreciation from his "". (TV: Spyfall)

Babbage met the Thirteenth Doctor when the latter arrived in 1834 London, where Babbage was displaying one of his innovations at a scientific exhibit at the Adelaide Gallery. Afterward, the Doctor accompanied him and his assistant Ada Lovelace to Babbage's dwelling, where he introduced the Doctor to the difference engine. Babbage explained that once finished, his invention would count and perform quadratic equations. He then introduced her to the Silver Lady. According to Babbage it was "a revolutionary piece of engineering", though he thought it to be as much for decoration as for purpose, "like all great ladies". He told the Thirteenth Doctor that it moved and, on occasion, projected. These "projections" turned out to be the Kasaavin. (TV: Spyfall)

The same year, the Star Chamber approached him to build a more advanced version of the difference engine, called the analytical engine. (PROSE: The Book of the War)

By the 1890s, Babbage had passed away. After his death, "the Colonel" purchased some of his notebooks for a large amount of money. The Colonel used the knowledge from the notebooks to construct probability that he christened Babbage engines. The Babbage engines served as the thought centres of his Sentinels, artificial mechanical creations with which he planned to take control of the entirety of Europe. (AUDIO: Military Intelligence)

Alternate timelines
In an alternate timeline created by the Oracle, Babbage was killed by William Kempton. (PROSE: The Domino Effect)