13th February

In the early hours of this day 1535, inspiration came to Niccolò Tartaglia and he discovered a method of solving 'squares and cubes equal to numbers'. (That is equations of the form

x^3 + ax^2 = b

). This allowed him to win his contest against Fior in Venice. See THIS LINK.

The postage stamp of one of today's mathematicians at THIS LINK was issued in 1983.