John 18:13

And led him away to Annas first
Who is elsewhere mentioned with Caiaphas as an high priest also, ( Luke 3:2 ) ( Acts 4:6 ) . He was the "sagan" of the high priest; he and Caiaphas seem to have had the high priesthood alternately; and either now, because his house lay first in the way, or rather, because he was a man of age, learning, and experience, as these men usually were, that they might supply the deficiencies of the high priests, who were sometimes very weak and unlearned men ^F11; therefore they first lead him to him, to have his advice how to proceed, and to take him along with them to his son-in-law, where the great council was convened, and that he might use his interest and authority, in taking proper measures, in order to put Jesus to death; and especially they led him to him, for the reason here assigned;

for he was father-in-law to Caiaphas;
so that he was, it is very probable, the older man: and being related to him, had an interest in him; and to whom such a sight was equally pleasing as to the high priest himself, or any of the council:

which was the high priest that same year;
for the high priesthood was not for life, but was often changed, being bought and sold for money; (See Gill on Luke 3:2); so that this clause is very properly added, though Caiaphas held it longer, or, at least, had it more years than one; for Caiaphas was high priest when John began to preach, ( Luke 3:2 ) ; but he now succeeded Simeon ben Camhith, who was priest the year before; as was Eleazar the son of Ananus, the year before that; and before him Ishmael ben Phabi, who were all three successively put into the priesthood by Valerius Gratus, the Roman governor; as was also Caiaphas this year, and whose name was Joseph.