Historically Jesus was really here so Jesus was not "invented."
Jesus, as portrayed in the Bible, was never here. Outside of the Bible, there are practically zero historical documents speaking of him. But sure, there were lots of people who believed they were the Messiah back in those days, just like there are today:
http://en.wikipedia.org/wiki/List_of_messiah_claimantsBasically a rundown of historical sources outside of the bible supporting the existence of Christ.