1886 – Paul Pierre Lévy, born on the 15th of September in Paris, France. He was a French mathematician who was active especially in probability theory, introduced martingales and Lévy flights.
1905 – Attended the École Polytechnique and published his first paper at the age of 19, while still an undergraduate.
1913 – After graduation he spent a year in military service and then studied for three years at the École des Mines, where he became a professor.
1920 – He was appointed Professor of Analysis at the École Polytechnique, where his students included Benoît Mandelbrot.
1959 – He remained at the École Polytechnique until his retirement.
1971 – Died on the 15th of December iin Paris, France.