Adjusted knowledge:
One could make an argument for a historical Jesus. I've only know of Flavius Josephus that made mention of Jesus around that time period (outside the writings of Jesus disciples). Josephus' reference was a vague reference too.
There's actually 3 'early' references to jesus outside of the bible. Two by Josephus and 1 by Tacitus. The Josephus references were written in AD 93/94. One, even christian scholars agree, was tampered with by early christians though to what extent isn't know although the core document was still thought to be intact.
The Tacitus reference was written in AD116.
The issue here is that they were not first-hand accounts. One was written 60 years after jesus' supposed death and the other a fully 83 years. So, what were the bases of these documents?
Some scholars have even questioned the authenticity of these documents.