The fact that He seems to have been referred to as a Messiah during His lifetime is one thing that suggests to me that He actually was a military leader. 1st century Judea had many guerilla warriors fighting against the Roman occupation and the Jewish lackeys who profited from helping them stay in control. Jesus was executed for treason by Pilate.They wanted a military leader as a messiah, and Jesus didn't fit that bill.
But, of course, His Apostles couldn't tell a Roman agent like Saul of Tarsus any of that. The version of the Jesus legend that they gave him became a new religion when he went out proselytizing in the name of Jesus the Christ.
It came to be known as Christianity. Eventually.
Tom