Simon bar Kokhba was a Jewish military leader, who led an unsuccessful revolt against the Romans in 132-135 A.D. Originally, named Simon Bar Koziba, he was given the name Bar Kochba ("Son of a Star" in Aramaic) by the Jewish sage Rabbi Akiva (or Akiba), who supported the revolt and contemplated the possibility that Bar Kochba, if he were successful, would be the long-awaited Jewish Messiah.

Despite some initial successes, the revolt was brutally crushed by Hadrian: Bar Kochba and his followers were killed in a dramatic last stand at the fortress of Betar, southwest of Jerusalem, and many of his supporters were executed, among them Rabbi Akiva. Nevertheless, it was a costly victory for Rome, and the generals, when reporting to the Senate, did not begin with the customary greeting: "I and my troops are well." After Bar Kokhba's defeat, Jerusalem was razed, Jews were forbidden to live there, and a new Roman city, Aelia Capitolina, was built in its place.

Over the past few decades, much new information about the Bar Kokhba Revolt has come to light, thanks mainly to the discovery of several collections of letters, some possibly by Bar Kokhba himself, in the caves overlooking the Dead Sea. These letters can now be seen at the Israel Museum.