Simon bar-Kokhba ("Son of a star"; originally named "bar-Koziba"; later referred to by Jews as "bar-Kosiba", "son of a lie") was the last significant false Messiah. In 130 AD, Emperor Hadrian forbade Jews from visiting Jerusalem and ordered that a temple to the idol Jupiter be constructed on the site of the Second Temple, ruined since the revolt of 70 AD.. Two years later, bar-Kokhba began a revolt.
Akiba used to expound, A star (כוכב)goes out from Jacob [Num 24:17], ‘Koziba (כוזבא) goes out from Jacob.’ When R. Akiba saw Bar Koziba, he said, “This is the king messiah.” (דין הוא מלכא משיחא) R. Yohanan b. Torta said to him, “Akiba, grass will come up between your cheeks and still the son of David will not have come.” 
Bar-Kokhba called himself "Nasi," or "Prince," a term used to describe Messiah. Coins were even minted with his picture on them, showing him holding Aaron's rod that had budded. He persecuted Christians who would acknowledge only Jesus as Messiah.
Bar-Kokhba was a detail-oriented administrator, taking charge of even such details as the distribution of individual donkeys and ensuring adherence to the Mosaic Law His Jewish state lasted for almost three years and covered most of Judea. He reconviened the Sanhedrin at his headquarters in Betar (southwest of Jerusalem), making Rabbi Akiba its president.
The Jews fought tenaciously. Emperor Hadrian had to personally come to Judea with at least four whole legions, one of which was probably annihilated in the war. The Romans razed many Jewish towns and murdered masses. Finally, in the winter of 135-136 AD, they pushed bar-Kokhba back to his headquarters at Betar, where he and his last defenders never surrendered but died from hunger and thirst in the besieged town. So many Romans had perished in the war that Hadrian, in writing to the Roman Senate, refused to employ the opening phrase commonly affected by the emperors: 'If you and your children are in health, it is well; I and the army are in health.'
With Bar-Kokhba perished the last Jewish state or army until the 1900's. Hadrian razed Jerusalem and forbade Jews from studying the Torah or circumcising their children. Forever after, Messianic claims were suspect among the Jews. The Mishnah omits many mentions of Messiah, and it apologizes for Akiba's obviously-wrong recognition of bar-Kokhba. The Jewish rabbis even refused to use his real name or semi-Messianic title, calling him instead "bar-Kosiba," "son of a lie."
- ↑ 1.0 1.1 http://www.livius.org/ja-jn/jewish_wars/jwar07.html
- ↑ 2.0 2.1 http://www.jewishvirtuallibrary.org/jsource/biography/Kokhba.html
- ↑ y. Taʿan. 4:8/27; parallel at Lam. Rab. 2:2 §4
- ↑ E.g. Ezekiel 34:24
- ↑ Justin Martyr, First Apology 31:6
- ↑ Cassius Dio, Roman history 69.14.3