Eusebius of Caesarea (ca. 263 - 339) is often called "The Father of Church History". He became the bishop of Caesarea Palaestina around 314. Ecclesiastical History was written during the latter part of Eusebius' life. It gives a chronological account of the Christian Church starting in the first century.
Thomas À Kempis (ca. 1380 - July 25, 1471) was a German-born Catholic monk. The Imitation of Christ was originally published around 1418. It shows the importance and application of the principles of Christ's life to your own life.