TIDDIS. – An ancient diocese in Numidia, in present-day Algeria, now a titular see.
It is the ancient «Castellum Tidditanum», 40 km from Constantine. It is now a titular see. The oldest known bishop is Lampadius in 411; Abundius in 484. Near the mithraeum, a small Christian basilica and a baptistery have been discovered, whose basin is surrounded by four columns and is therefore called the basin of the four columns. In the midst of the pagan necropolis there are Christian burials, including one with a mosaic inscription; clay lamps bearing Christian symbols and a silver ring with and the wish «in Deo vivas» have been found there.
BIBL.: S. Gsell, Atlas archéol., sheet 17, no. 89; J. Mesnage, Afrique chrét., Paris 1912, pp. 315 and 434; A. Berthier, T. Castellum Tidditanum, Algiers 1951. Enrico Josi