The Corinthians (Acts 18:5-17)

Paul stayed in the city of Corinth for at least a year and a half, probably a bit longer.

At one point, the Jews opposed him too much and Paul in frustration declares that he will only go to the Gentiles.  The text then says that he went next door from the synagogue to the house of Titius Justus.  This sounds like he moved his place of preaching to directly next door to the synagogue.  If so, it kind of is a bit funny as it is passive-aggressive antagonizing of the Jews.  

He gets a principle convert in the ruler of the synagogue,  Crispus, and his family.  An event later on suggests that this led to the replacement of the synagogue ruler.  Alternatively, perhaps Crispus tells the Jews that they cannot use his building anymore.  Either way, this would have highly embarrassed the Jews.  Meanwhile, Paul is preaching next door to the old synagogue.  

The combinations of these would have kept tension high.  So, God speaks to Paul one night.  God tells him to not be afraid of people in the city because no one will harm him because God has a lot of people in the city.

This echoes of something that Elijah received from God.  God told Elijah that there were 10,000 believers in the northern kingdom despite King Ahab and Jezebel.  At that time, Elijah was desperate and lonely.  Here, Paul is not stated as feeling that kind of persecution.  That said, Paul is aware that things can change quickly and deadly like the incident in which he was stoned.

The story immediately flows into a plot by the Jews against Paul.  The Jews take Paul before the Roman court and accuse him of religious crimes against the Roman proconsul Gallio.  This seems to fit the situation that God warned Paul about.

Paul is about to speak, but Gallio speaks first.  He basically says that his court has no jurisdiction over these religious matters.

What is missing from the Jews' charges is what they said about Jesus before Pilate.  If they had said something about proclaiming another king, then this might have forced Gallio to do something about Paul.  However, given God's warning about more believers in the city, Gallio may have been a silent believer or at least sympathetic to the Christians.

The Jews are thrown out of the court before Gallio.  They then turn on their synagogue ruler, Sosthenes, and beat him up.  Gallio does not care.  His indifference to this mob justice might show his annoyance with the Jews or perhaps a sympathy to the Christians.

Probably, Sosthenes was the mastermind of this plot against Paul and the Jews blame their embarrassment on him.  Likewise, since the name of the synagogue is different, it shows that either the synagogue ruler has been replaced or that the synagogue itself was replaced.