day" interchangeably. Ancient estimates Other estimates of the chronology of Jesus have been proposed over the centuries. Hippolytus, around AD 200, dates his birth as on Wednesday the eighth day to the Kalends of January (25 December) in the 42nd year of Caesar Augustus. This may refer to 2, 3, or 4 BC (it is not certain how much knowledge Hippolytus had of the calendar at that time, which was perturbed). There is some disagreement between manuscripts, but in any case he seems to have believed that the incarnation was on the 25th of March and the birth nine months later. He dates the crucifixion to the 33rd year of the life of Christ, on Friday 25 March of the 18th year of Tiberius. The reign of Tiberius began in AD 14, but 25 March never fell on a Friday between AD 30 and AD 34 inclusively. Eusebius, in his work Historia Ecclesiae first published in AD 313, placed the birth of Jesus in the forty-second year of Augustus' reign, and the twenty-eighth after the subjugation of Egypt and the deaths of Antony & Cleopatra, i.e. in 3 BC. The 3rd/4th century Roman historian Lactantius states that Jesus was crucified on 23 March AD 29. Maximus the Confessor and Cassiodorus asserted that the death of Jesus occurred in AD 31. In AD 525 Dionysius Exiguus devised an Easter table to calculate the dates of Easter at a time when Julian calendar years were still being identified by naming the consuls who held office that year – Dionysius himself stated that the "present year" was "the consulship of Probus Junior", which was 525 years "since the incarnation of our Lord Jesus Christ". Thus Dionysius implied that Jesus' incarnation occurred 525 years earlier. Bonnie J. Blackburn and Leofranc Holford-Strevens briefly present arguments for 2 BC, 1 BC, or AD 1 as the year Dionysius intended for the Nativity or incarnation. Among the sources of confusion are: In modern times, incarnation is synonymous with the conception, but some ancient writers, such as Bede, considered incarnation to be synonymous with the Nativity. The civil or consular year began on 1 January but the Diocletian year began on 29 August (30 August in the year before a Julian leap year). There were inaccuracies in the lists of consuls. There were confused summations of emperors' regnal years. It is not known how Dionysius established the year