According to Matthew 27:37
And set up over his head his accusation written, THIS IS JESUS
THE KING OF THE JEWS.
According to Mark 15:26
And the superscription of his accusation was written over, THE
KING OF THE JEWS.
According to Luke 23:38
And a superscription also was written over him in letters of
Greek, and Latin, and Hebrew, THIS IS THE KING OF THE JEWS.
According to John 19:19
And Pilate wrote a title, and put it on the cross. And the
writing was JESUS OF NAZARETH THE KING OF THE JEWS.
Which one is right? We could look at contemporaneous historians but, well there are none. The closest was Josephus but he is silent on the details (and it is disputed if he even wrote of Jesus at all).