NAISSUS(Ναϊσσός, Steph. B. s. v.;Νᾶσσος, Ptol. 3.9.6; Νάϊσος, Zosim. 3.11; Ναῖσός, Hierocl. p. 654), an important town in Upper Moesia, situated in the district Dardania, upon an eastern tributary of the river Margus, and upon the military road running through this country. It was in the neighbourhood of Naissus that Claudius II. gained his victory over the Goths in A.D. 269 (Zosim. 1.45); but the town is chiefly memorable as the birthplace of Constantine the Great. (Steph. B. s. v.;Const. Porph. de Them. 2.9. p. 56, ed. Bonn.) It was destroyed by the Huns under Attila (Priscus, p. 171, ed. Bonn.), but was restored by Justinian (Procop. 4.1, where it is called Naisopolis). It still exists under the name of Nissa, upon the river Nissava, an affluent of the Morava.