Who Arrested Jesus and Why?

Growing up I was under the impression that the tyrant Romans were the one who arrested and crucified Jesus.
I also was taught that Jesus was crucified because he proclaimed that he was God.
This isn't the case with all teaching of Christianity, but I am putting this info out there for anyone who may have been under the same impressions about these events as me.

We will start with the arrest and since the arrest was in all 4 accounts of the Gospels, we will go through each one.

Mark 14:43-52  
"With him was a crowd armed with swords and clubs, sent from the chief priests, the teachers of the law, and the elders."
So a crowd sent by the "chief priests" which were teachers of the law and the elders. The ones they are referring to here are the Sanhedrin , The Sanhedrin were responsible for the religious laws of the Jews not governmental or civil laws. Romans are not mentioned here at all.  He is then taken to the Sanhedrin for questioning then taken to the Romans.


Luke 22:47-53
"While he was still speaking a crowd came up, and the man who was called Judas, one of the Twelve, was leading them"
"Then Jesus said to the chief priests, the officers of the temple guard, and the elders, who had come for him"
Pretty much same as Mark's account.

Matthew 26:47-56 
"With him was a large crowd armed with swords and clubs, sent from the chief priests and the elders of the people."
And of course Matthew also agrees.

John 18:1-12 
"So Judas came to the garden, guiding a detachment of soldiers and some officials from the chief priests and the Pharisees"  
This is the only passage i see that could possibly hint toward the Romans involvement in the arrest. the detachment of soldiers and in verse 12 they even have a commander.
But reading further John 18:28-31  After the trial of the Sanhedrin they bring Jesus to Pilate and he has no clue why they brought him there, in fact he tells them to take him and judge him themselves.
"So Pilate came out to them and asked, “What charges are you bringing against this man?”"... "Pilate said, “Take him yourselves and judge him by your own law.”" 
 If the prefect of Judea for the Roman army didn't know anything about the arrest, then the soldiers mentioned obviously didn't belong to the Romans. 

Now moving on to why Jesus was arrested, and why he was crucified.
Jesus' teaching stirred up a lot of attention, the priests heard that people were calling Jesus the Messiah and falsely claiming to be the Messiah was blasphemy.
They had no basis for arresting him but they schemed and plotted and knew that his disturbances need to be stopped.

Mark 14:48-49
"Every day I was with you, teaching in the temple courts, and you did not arrest me."
Mark 14:55-59 
"The chief priests and the whole Sanhedrin were looking for evidence against Jesus so that they could put him to death, but they did not find any."
They had nothing to go by for arresting Jesus and even after the arrest they couldn't find any evidence. Even the false testimonies of people didn't hold up. 

Matthew 26:59 
same as Mark's account
Matthew 26:62-68 

After admitting he was the Messiah, with no such proofs but his words they struck him and while striking him they mocked him for claiming to be the Messiah.
⁶⁷ Then they spit in his face and struck him with their fists. Others slapped him ⁶⁸ and said, “Prophesy to us, Messiah. Who hit you?”

Luke and John proclaim the same thing, Jesus is arrested for claiming to be the Messiah. While the priests are unable to put to death Jesus for this under their law since they have no proofs that he isn't the Messiah, they bring him to the Romans who will put to death anyone who claims to be a "King" next to Caesar.

Mark 15:1-15
² “Are you the king of the Jews?” asked Pilate.
“You have said so,” Jesus replied.
Jesus was crucified because of his admittance to being a "King" not because of any other claim. In fact Pilate tries to save Jesus by customarily releasing him and gave the crowd a choice between Jesus and a murderer Barabbas, the chiefs stir the crowd to have Pilate release Barabbas instead.
⁹ “Do you want me to release to you the king of the Jews?” asked Pilate, ¹⁰ knowing it was out of self-interest that the chief priests had handed Jesus over to him. ¹¹ But the chief priests stirred up the crowd to have Pilate release Barabbas instead.

After being handed over for crucifixion, they put a crown of thorns over his head and a purple robe, and mocked him for his claim for being King of the Jews.
Mark 15:16-20 
¹⁸ And they began to call out to him, “Hail, king of the Jews!”

Summary of the facts:
1) It was the Jewish priests of the Sanhedrin, that plotted and arrested Jesus for his disturbances and claims of being the long awaited Messiah.

2) The priests could not conjure up any viable proofs that would condemn Jesus to death under Jewish law, so they brought him to the Romans for Jesus' claim of being a King.

3) Jesus was crucified for claiming Kingship next to Tiberius Caesar, which was considered treason and punishable by death .