Alan Turing was a brilliant mathmatician and logician. He served the British government for many years, but his most well-known contribution was during WWII when he fought for the allies as a code-breaker. He was the one who finally broke the Enigma code, which was the encrypting device used by the Nazis during WWII. Because of his actions the Allied forces were able to predict and counter their attacks. Later in life Turing was charged for "gross indecency" (Last Years) because he was gay. He was then forced to undergo chemical castration therapy and was found dead a few years later from cyanide poisoning. 

Alan Turing was very similar to Florence Nightingale in the amount of impact he had. Florence Nightingale was able to change the course of modern medicine by her practice and her work led to germ theory. Because of her work, millions have been saved. Alan Turing did similar things in his work for the British government. His work on the Enigma immediately saved thousands of lives, but also could have potentially saved millions. His work also helped lead to the invention of the modern computer, and his was some of the first work done for artificial intelligence. Both of these people were very intelligent and changed the course of history with their actions. 

Sources: https://www.britannica.com/biography/Alan-Turing

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