Tiddis was a Roman city that depended on Cirta and a bishopric as Tiddi, which remains a Latin Catholic titular see. It was located on the territory of the current commune of Bni Hamden in the Constantine Province of eastern Algeria.
Icosium was a Berber city that was part of Numidia which became an important Roman colony and an early medieval bishopric in the casbah area of actual Algiers.