Wouldn't that be the Tribes of Israel? 
Neither. There are a lot of other options in there.
As historical speculation, I suspect there was such a preacher named Joshua at that time, simply considering the commonality of that name. Monty Python's Life of Brian exaggerated, but the scene with the street of rival preachers was not all that far off the historical truth.
That said, this Joshua attracted a following and had some wisdom in what he said. Quite possibly, he got in trouble with the Roman law. After his death, his followers collected stories on him, some accurate; some the works of other men, attributed to Jesus, some -- well, George Washington had his Parson Weems.
In a religious sense, it is irrelevant to me. Judaism in unusual in that it sees itself as the religion of one people only -- the Tribe of Israel -- but does not deny that people of other religions may be righteous. Furthermore, Jewish belief is that the righteous non-Jew has the same reward in the afterlife as the righteous Jew. The difference is that the non-Jew is subject to Noahic law; the Jew is subject to Jewish.
Christianity is the way God for the righteous Christian. Islam is the way to God for the righteous Muslim (not as many of them around, anymore, a there used to be). Buddhism is the way to God for the righteous Buddhist. Atheism is the way to God for the righteous atheist -- and won't they be pleasantly surprised?
Check back later to see if it evolves ...
Wouldn't that be the Tribes of Israel?
No, either Jesus spoke the truth, or He is a liar. He is God, or he is not God. If you study the Bible intead of Life of Brian, you would know He has given you the choice to accept His redemption, but His Truth is not in doubt.