Jamieson, Fausset and Brown on Acts 28:17-20

17-20. Paul called the chief of the Jews together--Though banished from the capital by Claudius, the Jews enjoyed the full benefit of the toleration which distinguished the first period of Nero's reign, and were at this time in considerable numbers, wealth, and influence settled at Rome. We have seen that long before this a flourishing Christian Church existed at Rome, to which Paul wrote his Epistle (see on Ac 20:3), and the first members of which were probably Jewish converts and proselytes. (See Introduction to Romans.)

yet was I delivered prisoner from Jerusalem into the hands of the Romans--the Roman authorities, Felix and Festus.