You do actually realize that there is NO definitive proof nor evidence that this Christ existed don't you?
However, there is written evidence from the records kept of the 3 Councils of Nicaea that the ENTIRE story, including approx. 99.86% of the WHOLE bible was invented at those Councils solely for the purpose of legitimising the Monotheist belief system that later became known as Christianity.
Roman Emperor, Constantine was in a huge bind when he was start his 'take-over' attack' on the last of his opponents to make himself SOLE Emperor of the Roman Empire.
He desperately NEEDED the backing of the then Messianic Cult to bolster his forces so he created the the Prophetic dream that he had seen a sign from the Messianic God emblazoned across the sky above Rome and that should the Messianics join forces with his Roman Legions, then on his Victory, he would ensure that their beliefs were accepted into Roman culture, etc, etc.
Later, on his death-bed, Constantine recanted the entire 'sign from God' story, refused to be baptised and proclaimed himself to be a Divinity just as was Gaius Julius Caesar.