Caiaphas was the son-in-law of Annas, one of several High Priests from the House of Annas. He was appointed by Roman governor Gratus in 18 CE and confirmed under Pontius Pilate.
Caiaphas ruled for almost 20 years. His tenure was the peak of power of the House of Annas.
Caiaphas was the High Priest at the time of John the Baptist and Jesus of Nazareth. According to Christian sources he (and Annas) played an active role in the condemnation of Jesus. Caiaphas continued to harass the Jesus movement, by questioning Peter and John, condemning Stephen to death, and hiring Paul of Tarsus in a violent persecution against the Christian Hellenists.
In 36 CE, with the removal of the Roman governor Pilate, Caiaphas also was dismissed and succeeded by another member of the House of Annas, Jonathan ben Ananus.
Caiaphas' family tomb was discovered and excavated by archaeologists in November 1990.
Matthew 26:3 -- Then the chief priests and the elders of the people gathered in the palace of the high priest, whose name was Caiaphas,
Matthew 26:57 -- Then those who had seized Jesus led him to Caiaphas the high priest, where the scribes and the elders had gathered.
Luke 3:2 -- during the high priesthood of Annas and Caiaphas, the word of God came to John the son of Zechariah in the wilderness.
Acts 4:6 -- with Annas the high priest and Caiaphas and John and Alexander, and all who were of the high-priestly family.
John 11:49 -- But one of them, Caiaphas, who was high priest that year, said to them, “You know nothing at all.
John 18:13-14 --  First they led him to Annas, for he was the father-in-law of Caiaphas, who was high priest that year.  It was Caiaphas who had advised the Jews that it would be expedient that one man should die for the people.
John 18:24 -- Annas then sent him bound to Caiaphas the high priest.
John 18:28 -- Then they led Jesus from the house of Caiaphas to the governor’s headquarters. It was early morning. They themselves did not enter the governor’s headquarters, so that they would not be defiled, but could eat the Passover.