According to Procopius, the Byzantine emperor Justinian (527-565) reorganized the Cyrenaica, a project that is known as Ananeosis.note[Procopius, Buildings 6.2.] From now on, there was a permanent garrison in Antipyrgon, which protected a natural harbor, well sheltered against the prevailing northern winds. This port is still very important, as the events of the Second World War have shown.Fort Antipyrgon, which measured 270 x 200 meter, was not a new town; it had already been mentioned by Ptolemy of Alexandria.note[Ptolemy, Geography 4.5.] Archaeologists have on several places found parts of the massive wall that once surrounded the Byzantine fort. Along the waterfront, a substantial part is visible (look here).
Today, the port is known as Tobruk.