SEVERUS ° (sometimes called Serenus ), pseudo-messiah (or in some sources the Messiah's forerunner) in Babylonia about 720 c.e. The cataclysmic series of Muslim victories in the seventh century, culminating in the great Arab siege of Constantinople (717–8), provided the climate for an upsurge of messianic expectation among the Jews. In several Byzantine (both Greek and Syriac) chronicles Severus is described as a Syrian Christian who converted to Judaism. According to these sources, he attracted a large following, mainly of Jews but including some Christians, and gathered their money and assets, allegedly in order to bring them to the Promised Land. The Muslim authorities put him to death during the reign of Hisham (724–43). Severus introduced ritual innovations contrary to talmudic but not to biblical law, such as permission to work on the second days of holidays, modifications of kashrut laws, and the abolition of the prevalent marriage and divorce laws. After his death his followers, unlike those of such previous pseudo-messiahs as *Abu ʿIsā al-Iṣfahāni (c. 680s) and the Jew of Pallughta (Pumbedita?; 645), returned to the mainstream of Judaism, perhaps sending an inquiry to *Natronai Gaon (i). Severus was thought to have influenced Byzantine Jews and the risk of their affecting the loyalty of his other subjects may have been a reason for their persecution by Leo iii. Because of the impression he made on Christians, Severus continued to be mentioned in Christian sources until the 14th century.
J. Starr, in: rej, 102 (1937), 81–92; Baron, Social2, 5 (1957), 193ff., 380–2; A. Sharf, in: Byzantinische Zeitschrift, 59 (1966), 37–46; idem, Byzantine Jewry (1971), index.