SINGIDU´NUM(Σιγγί（ν）δουνον, or Σιγίνδουνον, Ptol. 3.9.3), a town in Moesia Superior, at the spot where the Savus falls into the Danubius, and on the main road along the banks of the latter river, opposite to the town of Taurunum ( Semlin) in Pannonia. ( Itin. Ant. p. 132; Itin. Hierosol. p. 563.) By Procopius ( de Aed. 4.6. p. 287) it is called Σιγγηδών.It was a fortress, and the head-quarters of the Legio IV Flavia Felix ( Not. Imp. ), the modern Belgrade.
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