section_path: History/The age of the world
section_name: The age of the world
paragraph_text: The age of the world
  
  The earliest extant Christian writings on the age of the world according to the biblical chronology are by Theophilus (AD 115–181) in his apologetic work To Autolycus, and by Julius Africanus (AD 200–245) in his Five Books of Chronology. Both of these early Christian writers, following the Septuagint version of the Old Testament, determined the age of the world to have been about 5,530 years at the birth of Christ.
  
  Ben Zion Wacholder points out that the writings of the Church Fathers on this subject are of vital significance (even though he disagrees with their chronological system based on the authenticity of the Septuagint, as compared to that of the Masoretic Text), in that through the Christian chronographers a window to the earlier Hellenistic biblical chronographers is preserved:
  
  An immense intellectual effort was expended during the Hellenistic period by both Jews and pagans to date creation, the flood, exodus, building of the Temple... In the course of their studies, men such as Tatian of Antioch (flourished in 180), Clement of Alexandria (died before 215), Hippolytus of Rome (died in 235), Julius Africanus of Jerusalem (died after 240), Eusebius of Caesarea in Palestine (260–340), and Pseudo-Justin frequently quoted their predecessors, the Graeco-Jewish biblical chronographers of the Hellenistic period, thereby allowing discernment of more distant scholarship.
  
  The Hellenistic Jewish writer Demetrius the Chronographer (flourishing 221–204 BC) wrote On the Kings of Judea which dealt with biblical exegesis, mainly chronology; he computed the date of the flood and the birth of Abraham exactly as in the Septuagint, and first established the Annus Adami (Era of Adam), the antecedent of the Hebrew World Era, and of the Alexandrian and Byzantine Creation Eras.