Who was Festus in the Bible

Festus was the Governor of Judea appointed by the Roman Empire to succeed Felix. He had presided over Paul’s case before sending Paul to Rome to be heard by Caesar as per the appeal filed by Paul.

When two years had elapsed, Felix was succeeded by Porcius Festus. And desiring to do the Jews a favor, Felix left Paul in prison. ACTS 24:27 ESV

Festus just wanted to do his job. He had been appointed by the Romans to replace Felix as governor of Judea, and in the transfer of leadership, he had inherited a unique prisoner named Paul.
Paul did not fit the reputation most people ascribe to prisoners. He was well educated and respectful, and he desired to live rightly before God and others. Why was he here?
The Jewish leaders had been hounding Festus to transfer Paul to Jerusalem to stand trial there (because they secretly wanted to assassinate him along the way), but Paul refused and appealed his case to Caesar. As Paul waited to leave for Rome, Festus discussed Paul’s case with some visiting dignitaries and called for Paul to speak to them to help him make sense of the case. As Paul spoke, Festus became so puzzled by what Paul was saying about Jesus that he called Paul insane.
Paul continued, however, and even tried to persuade the dignitaries themselves to become Christians.
After Paul was finished, the dignitaries informed Festus that Paul could have been set free if he had not appealed to Caesar, but Festus was now bound by Paul’s appeal, so he sent him to Rome.

The dignitaries who were visiting Festus were Agrippa II and his wife, Bernice. Agrippa II was the last of the descendants of Herod to rule over Judea, because it was during his reign that the First Jewish-Roman War (against the Romans) occurred, and after that the Romans took more direct control over the region.