Simon ben Kosiba, surnamed Simon bar Kochba ("son of the star") was a Jewish Messiah. Between 132 and 135, he was the leader of the last resistance against the Romans. After the end of the disastrous rebellion, the rabbis called him "Bar Koziba", which means "son of the lie".
Appian, whose account in the Syrian Wars is offered here in the translation by H. White, may give us the real cause of the revolt of Bar Kochba.
Appian on Bar Kochba
 The Jewish nation alone resisted, and Pompey conquered them, sent their king, Aristobulus, to Rome, and destroyed their greatest and to them holiest city Jerusalem, as Ptolemy, the first king of Egypt, had formerly done. It was afterward rebuilt and Vespasian destroyed it again, and Hadrian did the same in my time.