Zu Chongzhi, courtesy name Wenyuan, was a Chinese astronomer, inventor, mathematician, politician, and writer during the Liu Song and Southern Qi dynasties. He was most notable for calculating pi as between 3.1415926 and 3.1415927, a record in precision which would not be surpassed for nearly 900 years. 429 – 500; died at about 70. Alive at the same time as Justinian I, Boethius, Brendan the Navigator, Aryabhata, and Benedict of Nursia. Wiki link