Third, the Gospel of St. Luke (3:1) assigns the beginning of St. John the Baptist’s mission to the “fifteenth year of the Tiberius Caesar”. Augustus, the predecessor of Tiberius, died 19 August, 767 A.U.C., so that the fifteenth year of Tiberius’s independent reign is 782 A.U.C.; but then Tiberius began to be associate of Augustus in A.U.C. 764, so that the fifteenth year reckoned from this date falls in A.U.C. 778. Jesus Christ’s public life began a few months later, i.e. about A.U.C. 779.
The year of the death of Christ