The Church Fathers or Fathers of the Church are influential theologians and writers in the Church, particularly those of the first five centuries of Christian history. The term specifically refers to writers and teachers of the Church, not saints in general; usually it is not meant to include the New Testament authors.
Who are the Fathers?
Those fathers who wrote in Latin are generally called the Latin Fathers, and those who wrote in Greek the Greek Fathers. The very earliest Church Fathers, of the first two generations after the Apostles of Christ, are usually called the Apostolic Fathers.
Famous Latin Fathers include Tertullian, St. Augustine of Hippo, St. Ambrose of Milan, and St. Jerome, the translator of the Vulgate; famous Greek Fathers include St. Irenaeus of Lyons (whose work has survived only in Latin translation), Clement of Alexandria, Origen, St. Athanasius of Alexandria, St. John Chrysostom, and the three Cappadocian Fathers, Ss. Basil the Great, Gregory the Theologian, and Gregory of Nyssa. There are many more, however.
The Desert Fathers were early monastics living in the Egyptian desert; although they did not write as much, their influence was also great. Among them are Ss. Anthony the Great and Pachomius the Great. A great number of their usually short sayings is collected in the Apophthegmata Patrum.
A small number of other Fathers wrote in other languages: Ephrem the Syrian, for example, wrote in Syriac, but his works were widely translated into Latin and Greek.
Though the Roman Catholic Church regards the 8th century St. John of Damascus to be the last of the Church Fathers, the Orthodox Church does not consider the age of Church Fathers to be over at all and it includes later influential writers in the term.
The Consensus Patrum
It should be noted that not all of the Fathers are considered to be saints, and certainly none of them are regarded as infallible, most especially those who fell into heresy, such as Tertullian and Origen. The Orthodox Church looks rather to the consensus patrum—that is, the consensus of the Fathers—for its understanding of the patristic Orthodox faith.