Hypatia of Alexandria was a Greek mathematician and scientist living in Alexandria, Egypt who was martyred by a Christian mob in March 415. Her murder has come to symbolize all that was lost in the destruction of Pagan civilization by Christianity, and also the power of Pagan culture and its ability to endure despite intense and prolonged persecution. As she was engaged in a study of the timing of the northern hemisphere spring equinox at the time of her death, we observe the anniversary of her martyrdom on March 20.
More information about her is available at:
Hellenion voted in 2018 to add the anniversary of the anniversary of the martyrdom of Hypatia of Alexandria to our official calendar.