I attended the secondary school Lycée Buffon in Paris, being taught mathematics by the mathematician Jacques Hadamard.
Once Hadamard recognized my talent, he chose to tutor me on an individual basis...even when I moved away to attend the University of Bordeaux, he kept sending me mathematical problems and harshly criticized my errors.
WWI interrupted my plans to move to the U.S. and teach at the University of Illinois, being recruited to serve as an interpreter for the British Army near or at the front lines.
After the war, I never made it to the U.S., as I was asked to go to Strasbourg to help reestablish its university...and later taught mathematics in Paris until my retirement.
My main contributions were in the area of the topology of point sets, where I introduced the concepts of metric spaces and compactness (but did not coin the terms).
My other research publications focused on statistics, probability, and calculus, where I introduced the representation theorem in the space of Lebesgue square integrable functions.
Finally, I was an Esperantist, publishing multiple papers in the international language...even served as the president of the International Scientific Esperantist Association.
Maurice Fréchet (1878 - 1973)