John 18:15

Ἠκολούθει … μαθητής. “There followed Jesus Simon Peter” with whom the narrative is now concerned “and another disciple,” in all probability John. He is mentioned to explain how Peter found access to the high priest's residence. “That disciple was known to the high priest,” i.e., probably to Caiaphas, and accordingly went in with Jesus εἰς τὴν αὐλὴν τοῦ ἀρχιερέως, “into the palace (or court) of the high priest”. αὐλή, originally the court or quadrangle round which the house was built, was used of the residence itself. Apparently, and very naturally, Annas had apartments in this official residence now occupied by Caiaphas.