From the LCMS website:

Born c. 69, Polycarp was a central figure in the early church. A disciple of the evangelist John, he linked the first generation of believers to later Christians. After serving for many years as bishop of Smyrna, Polycarp was arrested, tried, and executed for his faith on February 23, c. 156. An eyewitness narrative of his death, The Martyrdom of Polycarp, continues to encourage believers in times of persecution.