Dioceses of the Church of the East after 1552 were dioceses of the Church of the East and its subsequent branches, both traditionalist (that were eventually consolidated as the Assyrian Church of the East) and pro-Catholic (that were eventually consolidated as the Chaldean Catholic Church).
Dioceses of the Eliya line, up to 1700
The traditionalist patriarch (1539–1558), who resided in the monastery of Rabban Hormizd, consecrating two metropolitans, for Nisibis, nominally with jurisdiction also over Amid and Mardin, and Joseph for Gazarta. was probably unable to exercise his authority in Amid and Mardin, both of which had Catholic metropolitans, but Joseph seems to have been accepted in Gazarta. 's nephew Eliya remained metropolitan of Mosul and natar kursya, and the Mosul and districts certainly remained loyal to VII.
The hierarchy of Eliya VI (1558-1591) Patriarch Eliya VI (1558-1591) had a hierarchy of at least six bishops: his brother , metropolitan of Mosul and natar kursya; Yahballaha, metropolitan of Berwari; Joseph and Gabriel, bishops of Gazarta; , metropolitan of Nisibis, and Yohannan, metropolitan of Urmi. Mosul was the chief traditionalist citadel, and Leonard Abel remarked in 1587 that although Sulaqa and his three successors had all been consecrated patriarchs 'of Mosul', none had been able to wrest the city from their traditionalist rivals. It now became customary in the Mosul patriarchate for the patriarch's natar kursya to be also metropolitan of Mosul.
The hierarchy of Eliya VII (1591–1617) According to the report from 1610, Eliya VII had six metropolitans (Eliya of Amid, Gabriel of Hesna d'Kifa, of Nisibis, Joseph of Gazarta, of Mosul and the natar kursya ), and nine bishops (Denha of Gwerkel, Yohannan of Abnaye, Ephrem of the Atel diocese of 'Ungi', of Seert, Yohannan of Atel, of Salmas, Joseph of Shemsdin, Abraham of Raikan and Abraham of 'the mountains'). This was a considerably larger hierarchy than his predecessors possessed, but all the metropolitans and several of the bishops are attested elsewhere, and there is no need to doubt its genuineness. Some of the dioceses are not mentioned again, and at least one bishop, of Seert, was the nephew and natar kursya of a metropolitan, for whom an ad hoc diocese had to be created.
Other sources mention several other bishops at this period. Although the two reports largely overlap, the report of 1607 mentions several bishops omitted from the report of 1610, including the metropolitans 'Glanan Imech' of Sinjar, of Erbil, Denha of Lewun, Yahballaha of Van and of Albaq; and the bishops Joseph of Nahrawan, Yohannan of 'Vorce', Yahballaha of Berwari and Abraham of Tergawar. The report did not mention their allegiances, but Yahballaha of Berwari is known to have been dependent on Eliya VII, and it is likely that the metropolitans of Sinjar and Erbil were also among his hierarchy. The metropolitans of Van and Abraham of the Persian district of 'Vehdonfores', probably the bishop of Tergawar mentioned in 1607, were present at Eliya VII's synod of Amid in 1616.
The hierarchies Eliya VIII (1617–1660) and Eliya IX (1660–1700) Eliya VIII (1617–60) did not consecrate bishops for the historic dioceses of Erbil, Nisibis, and Hesna d'Kifa, probably because their East Syriac communities were no longer large enough to need a bishop, and during his reign the Mosul patriarchate consisted of six metropolitan dioceses: Amid, Mardin, Gazarta, Seert, Mosul and Salmas. Although he corresponded cordially with the Vatican, he was not prepared to abandon the traditional Nestorian christological formula. As X had similar reservations, the Catholic communities in the Church of the East were left without Catholic bishops for several decades.
Dioceses of the Shimun line, up to 1700
The hierarchy of Shimun VIII Yohannan Sulaqa (1552–1555) Rome was told that the prime movers in the rebellion in 1552 against the patriarch were unnamed bishops of Erbil, Salmas and Adarbaigan, who were supported by many priests and monks from Baghdad, Kirkuk, Gazarta, Nisibis, Mardin, Amid, Hesna d'Kifa 'and many other nearby places'; while according to Leonard Abel, writing in 1587, Yohannan Sulaqa's support came primarily from the towns of Amid and Seert and the neighbouring country districts. Sulaqa is said to have consecrated five metropolitans and bishops during his brief patriarchate. They were almost certainly the metropolitans Eliya Asmar and Maron, consecrated by Sulaqa for Amid and Gazarta respectively in 1554, Sulaqa's brother Joseph, consecrated for Seert but soon afterwards sent to India, and the metropolitans Gabriel of Hesna d'Kifa and of Mardin.
The hierarchy of Abdisho IV Maron (1555–1567) According to Leonard Abel, IV Maron 'created many priests, bishops and archbishops, and many towns of Nestorian Chaldeans previously loyal to his rival placed themselves under his authority'. Abel may have gained this impression from a notorious letter which accompanied a Catholic profession of faith sent by to pope Pius IV in 1562. This letter, which survives in three slightly different Latin translations of a lost Syriac original, purports to contain a list of thirty-eight metropolitans and bishops who recognised his authority:
I, , son of Yohannan, of the house of Mari of the city of Gazarta on the Tigris river, was once a monk of the monastery of Saint Anthony and of the brothers Mar Ahha and Mar Yohannan, but am now, thanks to God and to the Apostolic See, Primate or Patriarch of the eastern city of Mosul in Athor, under whose jurisdiction are many metropolitans and bishops. These include the metropolis of Arbel [Erbil], and the dioceses of Sirava [Shirawa] and Hancava []; the metropolis of Cheptian [Telkepe] and the dioceses of Charamleys [Karamlish] and Achusch [Alqosh]; the metropolis of Nassibin [Nisibis], and the dioceses of Macchazin, Tallescani and Mardin; the metropolis of Seert and the diocese of Azzen [Hesna d'Kifa]; the metropolis of Elchessen [Gazarta] and the dioceses of Zuch [Zakho] and Mesciara [Mansuriya]; the metropolis of Gurgel [Gwerkel] and the diocese of Esci [Shakh]; and the metropolis of Amed [Amid] and the dioceses of Chiaruchia [Sharukhiya], Hain and Tannur []. All these regions are under Turkish rule.
Also the metropolis of Ormi Superior [Upper Urmi], and the dioceses of Ulcismi and Chuchia; the metropolis of Ormi Inferior [Lower Urmi] and the dioceses of Dutra, Saldos [Sulduz] and Escinuc [Eshnuq]; the metropolis of Espurgan [Supurghan] and the dioceses of Nare [Neri] and Giennum [Gawilan?]; the metropolis of Salmas, and the dioceses of Baumar, Sciabathan [Shapatan] and Vasthan [Wastan]. All these regions are subject to the emperor (or Sophi, as he is usually known) of the Persians.
Furthermore, in India, subject to the Portuguese, are the metropolitan dioceses of Cochin, Cranganore, and Goa; and the diocese of Calicut, which also includes the Coromandel region, still in the hands of heathen natives.
The status of this letter has long been recognised as problematical, as the fourth Catholic patriarch had only fourteen bishops in 1580, and it is unlikely that had a far larger hierarchy several years earlier. The locations of the fourteen metropolitan sees listed (with the exception of Telkepe) have a certain plausibility, but several of the suffragan dioceses were little more than villages. None of them, as far as is known, had previously been the seat of a bishop, and the bishops they supposedly had in 1562 are not mentioned in any other source. It is possible that merely claimed to have fourteen dioceses (the same number as his successor), whose metropolitans or bishops were responsible for the various localities listed under each metropolis, and that the translator misunderstood his meaning. Alternatively, he may have deliberately exaggerated the size of his hierarchy to impress the Vatican. In either case, while perhaps confirming the existence of East Syriac communities in certain districts and villages at this period and indicating the areas where claimed support, the letter cannot be trusted as evidence for the number of bishops in his hierarchy.
As a guide to 's support the letter must be treated with caution. His claim to the western districts (Amid, Mardin and Seert had Catholic bishops, and he also controlled the monasteries of Mar Pethion in the Mardin district and Mar the Recluse in the Seert district) was perfectly reasonable, and he certainly had two metropolitans in India. His claim to the Erbil, Urmi and Salmas districts may also have been justified, in view of the support for Sulaqa from their bishops. Alqosh, however, was the stronghold of his rival , who also controlled Telkepe and Karamlish. perhaps felt obliged, as 'patriarch of Mosul', to assert a claim to the Mosul district, and may have had a bishop nominally responsible for the villages of the Mosul plain.
Several metropolitans and bishops mentioned in other sources can be plausibly assigned to 's hierarchy, and it is interesting to notice that their dioceses match many of the metropolitan dioceses listed by in 1562: Sulaqa's brother Joseph, metropolitan of Seert, responsible also for India from 1555; Eliya Asmar, metropolitan of Amid from 1554 to 1582; Abraham, metropolitan of Angamale in India; , metropolitan of Nisibis and Mardin; the future patriarch , metropolitan of Gazarta; Yohannan of Atel and Bohtan ('s 'Gwerkel'), martyred in 1572; the future patriarch , metropolitan of Salmas, Seert and Jilu; and Gabriel (and perhaps his successor ), bishop of Hesna d'Kifa.
The hierarchy of Shemon IX Denha (1581–1600) The fourth Catholic patriarch (1581–1600), under pressure from his Nestorian rival Eliya VII, abandoned the western centres of Amid and Mardin which had supported the union with Rome, and governed his church from the remote monastery of Mar Yohannan in the Salmas district. During his own lifetime he retained the loyalty of the western bishops, and strengthened the hierarchy he had inherited by creating several new dioceses beyond the western districts. His supporters, mentioned in a letter of 1580 to pope Gregory XIII shortly after his consecration, included not only the western bishops Eliya of Amid, of Mardin, Joseph of Seert, Yohannan of Atel and Joseph of Gazarta, (earlier loyal to Eliya VI), but also the metropolitans Joseph of Salmas, Sargis of Jilu, of Shemsdin, of 'Koma', three men (two named Denha and one named Addaï) listed merely as metropolitans, and the bishop Yohannan of 'Chelhacke'. 'Koma' was probably the monastery of Mar near the village of Komane in the district, while 'Chelhacke' may be a deformation of Slokh (ܣܠܘܟ), the Syriac name for Kirkuk.
The hierarchy of Shemon X (1600–1638) The allegiance of several districts shifted dramatically on the accession of the pro-traditionalist patriarch X in 1600, who divided his residence between Salmas and Qudshanis. 's return to the old faith was welcomed in some districts, enabling him to consecrate bishops for the Atel and Berwari districts, previously dependent on the Mosul patriarchs. On the other hand, the western bishops transferred their loyalty to the patriarch Eliya VII, mainly because he was felt to be more enthusiastic for the union with Rome than his rival, but perhaps also because they did not wish to be governed by a patriarch unable or unwilling to leave the remote Salmas district. These shifts gave the Mosul patriarchate control of a wide swathe of lowland territory stretching from Amid to Erbil, including the important towns of Amid, Seert, Gazarta, , Mosul and Alqosh, while X was left with the mountain districts of Bohtan, Berwari and Hakkari, and the Urmi district.
According to the report from 1610, X had only five metropolitans ( of Shemsdin, Sargis of Jilu, of 'the Persian borders', of Berwari and the natar kursya Addaï), and three bishops (Joseph of Urmi, Giwargis of Sat and of Atel).