Two days after Theodosius arrived in Constantinople, 24 November 380, he expelled the Homoiousian bishop, Demophilus of Constantinople, and surrendered the churches of that city to Gregory Nazianzus, the leader of the rather small Nicene community there, an act which provoked rioting.

Within few years of his departure, St. Gregory of Nazianzus called him the " Pillar of the Church ".

In the monastic library at Jarrow were a number of books by theologians, including works by Basil, Cassian, John Chrysostom, Isidore of Seville, Origen, Gregory of Nazianzus, Augustine of Hippo, Jerome, Pope Gregory I, Ambrose of Milan, Cassiodorus, and Cyprian.

The hymns are short poems going back in part to the days of Prudentius, Synesius, Gregory of Nazianzus and Ambrose ( 4th and 5th centuries ), but mainly the work of medieval authors.

9th century Byzantine manuscript illumination of I ConstantinopleHomilies of Gregory Nazianzus, 879-882

Gregory Nazianzus was of similar mind, wishing to unify Christianity.

Gregory of Nazianzus presided over part of the Council

The first order of business before the Council was to declare the clandestine consecration of Maximus invalid, and to confirm Theodosius ' installation of Gregory Nazianzus as Bishop of Constantinople.

Gregory was born in the family estate of Karbala outside the village of Arianzus, near Nazianzus, in southwest Cappadocia.

Gregory went on to study advanced rhetoric and philosophy in Nazianzus, Caesarea, Alexandria and Athens.

In 361 Gregory returned to Nazianzus and was ordained a presbyter by his father, who wanted him to assist with caring for local Christians.

Arriving at Nazianzus, Gregory found the local Christian community split by theological differences and his father accused of heresy by local monks.

By late 372 Gregory returned to Nazianzus to assist his dying father with the administration of his diocese.

Following the deaths of his mother and father in 374, Gregory continued to administer the Diocese of Nazianzus but refused to be named bishop.

Returning to his homeland of Cappadocia, Gregory once again resumed his position as bishop of Nazianzus.

Gregory established Eulalius as bishop of Nazianzus and then withdrew into the solitude of Arianzum.

Paul Tillich credits Gregory of Nazianzus for having " created the definitive formulae for the doctrine of the trinity ".

Following his death, Saint Gregory was buried at Nazianzus.

* McGuckin, John A. St. Gregory of Nazianzus: An Intellectual Biography.

Gregory of Nazianzus.

* J. Egan, " Gregory of Nazianzus and the Logos Doctrine ," J. Plevnic, ed., Word and Spirit: Essays in Honor of David Michael Stanley.

Saint Boniface ( c 680 – 750 ), Pope Gregory I ( c 540 – 604, r. 590 – 604 ), Adalbert of Egmond ( 8th century ), and priest Jeroen van Noordwijk, depicted in a 1529 painting by Jan Joostsz van Hillegom, currently on display at the Frans Hals Museum.

* Pope Gregory VII ( c 1020 – 85, r. 1073 – 85 )

These preaching friars, with the authorization of Gregory IX, adopted ( with some modifications, e. g. the substitution of the " Gallican " for the " Roman " version of the Psalter ) the Breviary hitherto used exclusively by the Roman court, and with it gradually swept out of Europe all the earlier partial books ( Legendaries, Responsories ), & c., and to some extent the local Breviaries, like that of Sarum.

Gregory was eventually called forth from his pit in c. 297 to restore to sanity Tiridates III, who had lost all reason after he was betrayed by Roman emperor Diocletian.

Gregory of Nyssa ( c. 335 – 395 ), believed that the Prophet Esaias ( Isaiah ) " knew more perfectly than all others the mystery of the religion of the Gospel.

* 1276 – Pope Gregory X ( b. c. 1210 )

Gregory the Great ( c 540 – 604 ) who established medieval themes in the Church, in a painting by Carlo Saraceni, c. 1610, Rome.

Gregory the Great ( c 540 – 604 ) administered the church with strict reform.

Pope Gregory V, né Bruno of Carinthia ( c. 972 – 18 February 999 ) was Pope from 3 May 996 to 18 February 999, a son of the Salian Otto I, Duke of Carinthia, who was a grandson of the Emperor Otto I the Great.

Pope Gregory VIII ( c. 1100 / 1105 – 17 December 1187 ), born Alberto di Morra, was Pope from 25 October 1187 until his death.

Pope Gregory IX ( c. 1145 / 70 – 22 August 1241 ), born Ugolino di Conti, was pope from 19 March 1227 until his death.

Gregory XI ( c. 1329 – 27 March 1378 ) was pope from 1370 until his death.

Pope Gregory XII ( c. 1326 – 18 October 1417 ), born Angelo Correr or Corraro, was Pope from 1406 to 1415.

Blessed Pope Victor III ( c. 1026 – 16 September 1087 ), born Daufer ( Dauphar ), Latinised Dauferius, was Pope as the successor of Pope Gregory VII from 24 May 1086, yet his pontificate is far less impressive in history than his time as Desiderius, the great Abbot of Monte Cassino.

* Gregory of Nazianzus, ( c. 329-c. 390 ), Christian theologian, bishop of Nazianzus in Cappadocia

* Gregory the Great, ( c. 540-604 ), theologian, sixty-fourth pope ( 590-604 ), and civil administrator of Rome

* Gregory of Tours ( c. 538 – 594 ), Frankish bishop and historian

* February 18 – Pope Gregory V ( b. c. 972 )

* December 17 – Pope Gregory VIII ( b. c. 1100 )

Pope Saint Gregory VII ( c. 1015 / 1028 – 25 May 1085 ), born Hildebrand of Sovana (), was Pope from 22 April 1073 until his death.