Simon bar Kokhba (Hebrew: שמעון בר כוכבא; died 135 CE) was the Jewish leader of what is known as the Bar Kokhba revolt against the Roman Empire in 132 CE, establishing an independent Jewish state which he ruled for three years as Nasi ("Prince"). His state was conquered by the Romans in 135 following a two and half-year war.
Documents discovered in the 20th century in the Cave of Letters give his original name, with variations: Simeon bar Kosevah (Hebrew: שמעון בר כוסבה), Bar Koseva (בר כוסבא) or Ben Koseva (בן כוסבא). It is probable that his original name was Bar Koseva. The name may indicate that his father or his place of origin was named Koseva(h), but might as well be a general family name.
The Jewish sage Rabbi Akiva indulged the possibility that Simon could be the Jewish messiah, and gave him the surname "Bar Kokhba" meaning "Son of the Star" in Aramaic, from the Star Prophecy verse from Numbers 24:17: "There shall come a star out of Jacob". The name does not appear in the Talmud but in ecclesiastical sources.Rabbinical writers subsequent to Rabbi Akiva did not share Rabbi Akiva's estimation of ben Kosiva. Akiva's disciple, Yose ben Halaphta, in the Seder 'Olam (chapter 30) called him "bar Koziba" (Hebrew: בר כוזיבא), meaning, "son of the lie". The judgment of Bar Koseba that is implied by this change of name was carried on by later rabbinic scholarship at least to the time of the codification of the Talmudim, where the name is always rendered "Simon bar Koziba" (בר כוזיבא) or Bar Kozevah (בר כוזבה).