The  Church Fathers,  Early Church Fathers,  Christian Fathers, or  Fathers of the Church were ancient and influential  Christian theologians and writers who established the intellectual and doctrinal foundations of  Christianity. There is no definitive list. The historical period during which they flourished is referred to by scholars as the Patristic Era ending approximately around AD 700 ( John of Damascus died in 749 AD,  Byzantine Iconoclasm began in 726 AD).

Source:   https://en.wikipedia.org/wiki/Church_Fathers