There are several interpretations of this acronym. Here, we look at the most common.
When crucifixions were commonplace, it was customary to affix a board at the top of the cross detailing the crimes of the crucified person. This board was called titulus cruces hence the name Titulus Cross or Proclamation Cross. The plaque is stylised as an upper beam on several crosses, including the Patriarchal Cross, Orthodox Cross and Papal Cross. Sometimes the lettering is carved onto the main cross beam (patibulum), without the additional upper bar. We still refer to this as a Titulus Cross.
The inscription is usually 'INRI' but other lettering can be used (see Lettered Crosses).
Roman procurator Pilate was reluctant to crucify Jesus because he could see no real justification. Indeed, he would rather have acquitted Jesus, but there was intense pressure for him to assert his authority and punish those who were deemed to have broken the law. He was anxious that no negative reports about his performance would be relayed back to the emperor.
At that time, Jews had a treaty with Rome for self-government, therefore acting as a king of the Jews went against Rome. The Jewish priests complained to Rome that Jesus was interfering with their self-rule and Pilate challenged Jesus to deny this. With no denial forthcoming, Pilate announced a 'guilty by default' verdict and the priests demanded the death penalty. The crime for which Jesus was crucified therefore was 'King of the Jews', and this was duly painted on the titulus.
The inscription was written in Latin (the official language of the Roman Empire), Greek (the international language of culture) and Hebrew (the religious language of the Jews)1. The Latin is: IesvsNazarenvsRexIvdæorvm which in English translates to: 'Jesus the Nazorean, King of the Jews'2.
(The plaque was also an attempt by the soldiers to mock Jesus, as they also did by placing a crown of thorns on His head and a scarlet robe over Him.)
In the Middle Ages the primary language in church was Latin. People were familiar with the IesvsNazarenvsRexIvdorvm phrase and it became customary for artists to abbreviate the lengthy wording to the initial letters: INRI.
A fragment of the titulus from the True Cross (the cross on which Jesus Christ was crucified) still exists and lies in the Church of Santa Cruces in Rome. Or at least, many people believe that a small wooden block, less than a foot long, is an original relic from 2,000 years ago. Many others hotly contest this. Still, if the story is true about the Roman emperor Constantine sending out his mother, Helena, as a missionary, then there may be some authenticity in the piece. Helena is said to have taken the titulus of Jesus' cross as an aid in spreading Christianity throughout the Roman Empire.
In the Eastern Orthodox Church, the letters INBI reflect the equivalent Greek text Iésous o Nazóraios o Basileus tón Ioudaión
There are several other interpretations of INRI, including: