31. Why was the inscription "The King of the Jews" used on the cross?

From the fact that the evangelists give us three different forms for the inscription over the cross it has been argued that they were not accurate in their portrayal of things and events.
There is, however, nothing here to disturb anyone.

Matthew 27:37 has it, "This is Jesus the King of the Jews," using probably the Greek form; St. Mark 15:26, "The King of the Jews," and Luke 23:38, "This is the King of the Jews," availed them­selves of the Roman form, and John 19:19, "Jesus the Nazarene, the King of the Jews," probably employed the Hebrew form.

Since the four accounts of the inscription do not differ in import the exact language of the insulting designation is of little or no consequence.