According to our accounts, the trial of Jesus before Pilate was short and to the point. Pilate asked him whether it was true that he was the king of the Jews. Almost certainly, this was the actual charge leveled against Jesus. It is multiply attested in numerous independent witnesses, both at the trial itself and as the charge written on the placard that hung with him on his cross (e.g., Mark 15:2, 26). Moreover, it is not a charge that Christians would have invented for Jesusfor a possibly unexpected reason. Even though Christians came to understand Jesus to be the messiah, they never ever, from what we can tell, applied to him the title king of the Jews. If Christians were to invent a charge to put on Pilates lips, it would be, Are you the messiah? But thats not how it works in the Gospels. The charge is specifically that he called himself king of the Jews.
Evidence that Jesus really did think that he was the king of the Jews is the very fact that he was killed for it. If Pilate asked him whether he were in fact calling himself this, Jesus could have simply denied it, and indicated that he meant no trouble and that he had no kingly expectations, hopes, or intentions. And that would have been that. The charge was that he was calling himself the king of the Jews, and either he flat-out admitted it or he refused to deny it. Pilate did what governors typically did in such cases. He ordered him executed as a troublemaker and political pretender. Jesus was charged with insurgency, and political insurgents were crucified.
The reason Jesus could not have denied that he called himself the king of the Jews was precisely that he did call himself the king of the Jews. He meant that, of course, in a purely apocalyptic sense: when the kingdom arrived, he would be made the king. But Pilate was not interested in theological niceties. Only the Romans could appoint someone to be king, and anyone else who wanted to be king had to rebel against the state.
And so Pilate ordered Jesus crucified on the spot. According to our records, which are completely believable at this point, the soldiers roughed him up, mocked him, flogged him, and then led him off to be crucified. Evidently, two similar cases were decided that morning. Maybe a couple more the day after that and the day after that. In this instance, they took Jesus and the two others to a public place of execution and fixed them all to crosses. According to our earliest account, Jesus was dead in six hours.