The central, most important historical fact is the resurrection of Jesus Christ. If Jesus was not resurrected from the dead, then the Christian Faith has nothing to offer. The video at the end of the following link provides important reasons as to why we can commit ourselves, unreservedly, to the historicity of the resurrection of Jesus Christ. If Jesus did rise from the dead, then all His claims are true. If all His claims are true, then He is the most important person in the History of the world, because He said of Himself:
"I am the Way, the Truth and the Life; no man comes to the Father except through Me."