Romans 16:3-4 : Salute Prisca and Aquila my fellow-workers in Christ Jesus, who for my life laid down their own necks; unto whom not only I give thanks, but also all the churches of the Gentiles. Prisca is short for Priscilla. This good woman and her husband first joined in work with Paul at Corinth (Acts 18:1-3). They next appear in active service to the Lord at Ephesus (Acts 18:24-26). Just when they endangered their own lives--"laid down their own necks"--for the life of Paul we are not informed. Probably it was during that uproar at Ephesus (Acts 19:33-41).
Paul and all the churches of the Gentiles gave thanks to them for what they had done for him. The many that Paul mentions by name were people he had worked with, who had gone to Rome from points where Paul had preached. One wonders how he had kept track of them in that day of inconvenient communications.