The Byzantine diocese of Chalkis was initially a suffragan of the Archdiocese of Corinth, but in the 9th century was transferred to the Metropolitan of Athens, remaining in the sway of the Patriarchate of Constantinople.
It was also known as Euripo, like it's mentioned in the Byzantine imperial Notitia Episcopatuum since emperor Leo VI the Wise (886-912).

Several of its Greek bishops are recorded, but some disputed :
Constantinus, signed in 458 a letter by the bishops of Greece to Byzantine emperor Leo I the Thracian after the murder by Coptic mobs of patriarch Proterius of Alexandria.

Lequien list before him Anatolius (in 363), but he was probably bishop of Beroea in Syria Prima (now Aleppo).

next Lequien inserts, by benefit of doubt, Iohannes Damasceno, whom he also lists as bishop of Euroea (in Phoenicia) alias Evaria, in Phoenicia.

Teodorus and Teofilattus, successive (?)
bishops of Euripus, participated in the 869–70 Church council held at Constantinople.
viz.
the Council of Constantinople of 879–880, both treating the fate of Patriarch Photios I of Constantinople.
The Byzantine diocese of Chalkis was initially a suffragan of the Archdiocese of Corinth, but in the 9th century was transferred to the Metropolitan of Athens, remaining in the sway of the Patriarchate of Constantinople. It was also known as Euripo, like it's mentioned in the Byzantine imperial Notitia Episcopatuum since emperor Leo VI the Wise (886-912).
Several of its Greek bishops are recorded, but some disputed :
Constantinus, signed in 458 a letter by the bishops of Greece to Byzantine emperor Leo I the Thracian after the murder by Coptic mobs of patriarch Proterius of Alexandria.
Lequien list before him Anatolius (in 363), but he was probably bishop of Beroea in Syria Prima (now Aleppo).
next Lequien inserts, by benefit of doubt, Iohannes Damasceno, whom he also lists as bishop of Euroea (in Phoenicia) alias Evaria, in Phoenicia.
Teodorus and Teofilattus, successive (?) bishops of Euripus, participated in the 869–70 Church council held at Constantinople. viz. the Council of Constantinople of 879–880, both treating the fate of Patriarch Photios I of Constantinople.
Chalcis