You have to love Luke's chronology in this Sunday's reading from Luke 3:1-6,
In the fifteenth year of the reign of Emperor Tiberius, when Pontius Pilate was governor of Judea, and Herod was ruler of Galilee, and his brother Philip ruler of the region of Ituraea and Trachonitis, and Lysanias ruler of Abilene, during the high-priesthood of Annas and Caiaphas, the word of God came to John son of Zechariah in the wilderness. He went into all the region around the Jordan, proclaiming a baptism of repentance for the forgiveness of sins, as it is written in the book of the words of the prophet Isaiah,
‘The voice of one crying out in the wilderness:
“Prepare the way of the Lord,
make his paths straight.
Every valley shall be filled,
and every mountain and hill shall be made low,
and the crooked shall be made straight,
and the rough ways made smooth;
and all flesh shall see the salvation of God.”
Luke clues us in as to the time when Jesus was baptized by his references to the rulers of the period. There is a margin of error as noted at Time.Graphics,
Tiberius became sole emperor on the death of his adoptive father, Augustus, on 19th August AD 14. However, it is a well- known fact that he had become co-regent with his ailing father two years earlier in AD 12. In that year, he was made supreme military commander over Caesar's armies and prov- inces. Ancient coins from Antioch dated AD 12 display the head of Tiberius and documents attest to his reign being fully in force from that time. Thus, his inauguration in AD 14 as emperor was only a formalisation of a that had begun two years earlier. Therefore, the fifteenth year of the reign of Tiberius would make it AD 26-27 correlating with the start of Christ's ministry and supporting the AD 30 date as the most likely date of his crucifixion.
Thank you St. Luke.
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