Claudius Lysias was the "chief captain," or commander, of the Roman troops (see also Ancient Empires - Rome) in occupied Jerusalem (see Bible Places) at the time that the apostle Paul was arrested there for preaching the Gospel (some of the most righteous people in the history of humanity found themselves locked up in Prison, with some of the most unrighteous people of humanity, for the "crime" of boldly proclaiming the Biblical Truth, regardless of who liked it or not). Claudius Lysias was Greek-born, as his name Lysias indicates. His Roman name, Claudius, was most likely adopted after he became a citizen, something that the apostle Paul wasn't concerned with - he was born in Roman-occupied territory, and was therefore, by chance, a Roman (political) citizen by birth. Both Paul and Lysias were apparently equally well-indoctrinated with the hyped notion of Roman "freedom," and both (Paul, very surprisingly, considering that it was the very same Roman military-based political system that deprived him of his liberty, and eventually, his life) readily and naively parroted the prescribed patriotic buzzwords e.g. "And the chief captain answered, With a great sum obtained I this freedom. And Paul said, But I was free born" (Acts 22:28 KJV)
The trouble began when the former Pharisee Paul preached the Gospel in Jerusalem to people who were not quite ready to "hear" it; the city was still filled with many people who were as spiritually blind and deaf as Paul was himself before his conversion On The Road To Damascus, and they were just as violent toward the Gospel as Paul had been. When the commotion was heard by the Roman troops, Lysias quickly restored order, by arresting Paul:
"And all the city was moved, and the people ran together: and they took Paul, and drew him out of the Temple [see also Temples and Physical and Spiritual Temples]: and forthwith the doors were shut. And as they went about to kill him, tidings came unto the chief captain of the band, that all Jerusalem was in an uproar. Who immediately took soldiers and centurions, and ran down unto them: and when they saw the chief captain and the soldiers, they left beating of Paul."
"Then the chief captain came near, and took him, and commanded him to be bound with two chains; and demanded who he was, and what he had done. And some cried one thing, some another, among the multitude: and when he could not know the certainty for the tumult, he commanded him to be carried into the castle. And when he came upon the stairs, so it was, that he was borne of the soldiers for the violence of the people. For the multitude of the people followed after, crying, Away with him." (Acts 21:30-36 KJV)
Although it was Paul who was taken away and put in chains, his accusers later whined that Lysias' troops used excessive force against them, the people who were trying to kill Paul:
"But the chief captain Lysias came upon us, and with great violence took him away out of our hands" (Acts 24:7 KJV)
It was after his arrest that Lysias discovered that Paul was a Roman citizen, and that the process of his arrest had violated Paul's civil rights:
"The chief captain commanded him to be brought into the castle, and bade that he should be examined by scourging; that he might know wherefore they cried so against him. And as they bound him with thongs, Paul said unto the centurion that stood by, Is it lawful for you to scourge a man that is a Roman, and uncondemned?"
"When the centurion heard that, he went and told the chief captain, saying, Take heed what thou doest: for this man is a Roman."
"Then the chief captain came, and said unto him, Tell me, art thou a Roman?"
"He said, Yea."
"And the chief captain answered, With a great sum obtained I this freedom."
"And Paul said, But I was free born."
"Then straightway they departed from him which should have examined him: and the chief captain also was afraid, after he knew that he was a Roman, and because he had bound him." (Acts 22:24-29 KJV)
While Paul was being held, his nephew heard of a plot to assassinate the apostle and it was reported to Lysias who then ordered Paul to be taken under military guard to the procurator Felix at Caesarea:
"And when Paul's sister's son heard of their lying in wait, he went and entered into the castle, and told Paul. Then Paul called one of the centurions unto him, and said, Bring this young man unto the chief captain: for he hath a certain thing to tell him."
"So he took him, and brought him to the chief captain, and said, Paul the prisoner called me unto him, and prayed me to bring this young man unto thee, who hath something to say unto thee. Then the chief captain took him by the hand, and went with him aside privately, and asked him, What is that thou hast to tell me?"
"And he said, The Jews have agreed to desire thee that thou wouldest bring down Paul to morrow into the council, as though they would inquire somewhat of him more perfectly. But do not thou yield unto them: for there lie in wait for him of them more than forty men, which have bound themselves with an oath, that they will neither eat nor drink till they have killed him: and now are they ready, looking for a promise from thee."
"So the chief captain then let the young man depart, and charged him, See thou tell no man that thou hast showed these things to me. And he called unto him two centurions, saying, Make ready two hundred soldiers to go to Caesarea, and horsemen threescore and ten, and spearmen two hundred, at the third hour of the night; And provide them beasts, that they may set Paul on, and bring him safe unto Felix the governor."
"And he wrote a letter after this manner:"
"Claudius Lysias unto the most excellent governor Felix sendeth greeting. This man was taken of the Jews, and should have been killed of them: then came I with an army, and rescued him, having understood that he was a Roman. And when I would have known the cause wherefore they accused him, I brought him forth into their council: Whom I perceived to be accused of questions of their law, but to have nothing laid to his charge worthy of death or of bonds. And when it was told me how that the Jews laid wait for the man, I sent straightway to thee, and gave commandment to his accusers also to say before thee what they had against him. Farewell."
"Then the soldiers, as it was commanded them, took Paul, and brought him by night to Antipatris. On the morrow they left the horsemen to go with him, and returned to the castle: Who, when they came to Caesarea, and delivered the epistle to the governor, presented Paul also before him" (Acts 23:16-33 KJV)
Fact Finder: What happened after Paul was delivered to Felix?
See Felix and Festus