Following his third journey to Asia (now Turkey) and Achea (Greece) and Macedonia, Paul returned with "loot", tithes collected from his followers, for the mother church in Jerusalem.

While there he was accused of false teachings by the Asiatic Jews, there for Pentecost, who had heard the pronouncements he made in Asia, and accused him of heresy and violating the Law. He was seized by a mob, and rescued by the Romans.

After being released from prison for inciting unrest, and foiling a plot by th Sanhedrin to kill him, he was sent to Caesarea to be judged by Felix, procurator of Judea.

Facing both Felix and Agrippa II,  he made his case and it was determined that he  should be returned to Jerusalem and be tried by authorities there, under Felix's protection.

Paul, however said "Send me to Caesar for justice."

He was hoping to go to Rome and this would be his opportunity, and as a Roman citizen it was his right to have Caeasar judge him.

Paul's voyage was eventful to say the least, shipwrecked on the Island of Malta, alive and well, accompanied by his shipmates, who were all saved as well..none lost due to Paul, who was visited by an angel assuring him of this.

 In Malta, he was bitten by a deadly snake but survived.  

Thus, the cult of  snake-holders , believing that Paul, protected because of his great faithfulness, tempt fate,  determine  to prove that their faith is as strong, many found wanting, die trying.

From Malta he travels, uneventfully, to Rome, where he is imprisoned.

Nero is Caesar.  It's around 64 AD.

I believe, and traditions says, that he is released after being acquitted of any wrong doing.

His mission takes him to Spain, it's believed, living up to his wish mentioned earlier, and there is a tradition of Paul having set up a church there.

In 68 AD, there was a great conflagration that leveled much of Rome, said to be on Nero's order. 

Paul returns to Rome  where there are  many friends , among others Priscilla and Aquilla and members of the British royal family (Re my blog, "Paul In Britain").  

It would stand to reason that,  hearing of the great persecution of the ecclesia, he would return to Rome to be with his people.

Contrary to popular myth,  Peter was not among the victims. He was martyred somewhere in Babylonia, in a manner unreported, whereas Paul was beheaded, because he was a Roman citizen..rather than being burned or torn apart by wild beasts..pauonbob