Cyrenaica was conquered by Muslim Arabs during the tenure of the second caliph, Omer Bin Khattab, in 643/44, After the breakdown of the Umayyad caliphate it was essentially annexed to Egypt, although still under the same name, first under the Fatimid caliphs and later under the Ayyubid and Mamluk sultanates. Ultimately, it was annexed by the Turkish Ottoman Empire in 1517 when it was part of the Tripolitania Vilayet.
The diocese was nominally restored in 1933 as Latintitular bishopric under the names of Erythrum (Latine) / Eritro (Curiate Italian) / Erythritan(us) (Latin adjective).,
It has been vacant for decades, having had the following incumbents, so far of the fitting Episcopal (lowest) rank, including an Eastern Catholic:
Antonio Cavaleri (1764.04.09 – 1788.09.15) as Auxiliary Bishop of Agrigento (Sicily, insular Italy) (1764.04.09 – 1788.09.15); succeeded as Bishop of Agrigento (1788.09.15 – death 1792.12.11)
Raimondo A. Vecchietti (1797.07.24 – 1801.01.26) without prelature, later Bishop of Colle di Val d'Elsa (Italy) (1801.01.26 – death 1805.02)
Michele de Vincenti (1817.04.14 – death 1827), without prelature
Giovanni Battista Rosani, Piarists (Sch. P.) (born Italy) (1844.01.22 – death 1862.08.08) as President of Pontifical Ecclesiastical Academy (1844.01.22 – 1847) and on emeritate
Giovanni Felix Jacovacci (1863.10.01 – 1879.06.10) (born Italy), no prelature
Victor van den Branden de Reeth) (1879.11.14 – 1897.12.04) as Auxiliary Bishop of Mechelen (Belgium) (1879.11.14 – 1909.02.27); later on emeritate 'promoted' as Titular Archbishop of Tyrus (Tyre) (1897.12.04 – death 1909.02.27)
↑"Byzantine_Dark_Age". Archived from the original on 2010-12-16. Retrieved 2011-02-24. Early Medieval and Byzantine Civilization: Constantine to Crusades (Tulane.edu,2011).