Why did the Roman Centurions do this? To understand, you must recall the Star Prophecy: The Radical, militant extremists among the Jews — the Sicarii assassins and the Zealots — believed that the coming Messiah would be a "warrior Messiah" who, like Joshua and David, would slaughter and subjugate the heathens. These Jews, a strong and vocal minority, were so convinced that YHWH-God meant for them to dominate the world that they drove (by force) the Jewish nation to war against the Roman Empire. Indeed, this notion of world domination was so prevalent amongst these militant extremist Jews that the Romans were well aware of their intentions. For example, numerous classical writers from the 1st century knew about their world domination aspirations: Please also recall that the Sicarii assassins frequently murdered Romans and alleged Roman collaborators, for decades in the lead up to the Jewish Revolt (66-70 AD). Thus, the Romans had legitimate reason to fear these Sicarri assassins, their Zealot allies, and the "Messianic" fervor that animated them. This is why the Roman Centurions dressed the Messiah up in royal purple robes — the clothing of the Roman Caesars, the Emperors. The Romans believed, and feared, that Jesus was a Zealot - Sicarii - Assassin - "Warrior Messiah". In direct response to their understanding of the Jewish "Star Prophecy", the Romans briefly bowed down to the Messiah to mockingly say, "you will conquer Rome, you will slaughter and subjugate the Roman Empire, you will do what no enemy has done in four hundred years, you will break us and force us to worship you and make us your slaves?!?" NOTE: It is interesting to note that Pilate was sent to Judea in 29 AD — exactly when John the Baptist began his pre-Messianic ministry (Luke 3:1). Author Glenn Kimball asserts that Pilate was sent into Judea by the Roman Emperor Tiberius specifically to investigate this John-Jesus Messianic movement, and to arrest and eliminate the Messianic claimant. This would have been specifically to thwart what the Romans legitimately saw as a grave threat to their national security — to wit, these brutal "Messianic" dreams of the extremist Sicarii assassins and their Zealot allies for world conquest and domination through slaughter and bloodshed.