Era
Vol. 1: A seculo VI usque ad 803
Date
May 599
Place
Regestum

Pope Gregory I writes to Callinicus, the Exarch of Italy, regarding a variety of affairs, including the recent military victory over the Slavs and the return of the Church of Koper to the Catholic creed.

Source
The register of letters of Pope Gregory I; multiple manuscript copies exist (cf. MGH edition cited below and this link); the following edition is based on:
B = Paris, Bibliothèque Nationale de France, ms. lat. 2280: , fols. 40r–41r; 9th/10th century copy; digitized and available online here.
Previous Editions
Paul Ewald and Ludwig Hartmann, eds., Gregorii I papae Registrum epistolarum, vol. 2: Libri VIII–XIV, Monumenta Germaniae historica, Epistolae 2, (Berlin 1899), doc. IX/154, pp. 154–55.
FIM Edition
Diplomatic edition based on B.
Transcription

Gregorius Callinico Exarcho Italiae.

Inter hoc, quod mihi de Sclavis victorias nunciastis, magna me lętitia revelatum esse cognoscitę, quod latores presentium de Capritana insula unitati sanctae Aecclesiae coniungi festinantes ad beatum Petrum ap[osto]lorum principem ab excellentia vestra transmissi sunt. In hoc enim contra hostes vestros amplius prevaletis, si eos quod Dei hostes agnoscitis sub iugo veri domini revocatis tantoque vestras causas apud homines fortiter agitis, quando Dei causas in ominibusa sincera ac devota mente feceritis.

Quod autem exemplar iussionis que vos pro scismaticorum defensione transmissa est mihi ostendi voluistis, pensare sollicite dulcissima mihi vestra excellentia debuit, quia, quamvis iussio ipsa subrepta est, non tamen in ea vobis preceptum est, ut venientes ad unitatem Aecclesiae repellatis, sed ut venire nolentes hoc incerto tempore minime compellatis. Unde necesse est, ut haec piissimisb  imperatoribus nostris suggererec festine debeatis, quatenus cognoscant, quod eorum temporibus scismatici cum omnipotentis Dei solacio et labore vestro sua sponte reverti festinant.

Que autem de insulę Capritane ordinatione decreverim, per reverentissimum fratrem et coepiscopum meum Marinianum vestra excellentia agnoscit. Illud vero cognoscite, quia me non modice contristavit, quod maior domi, qui petitionem episcopi volentis reverti suscepit, eam se perdidisse professus est, et postmodum ab adversariis Aecclesiae tenebatur. Quod ego non neglegentia, sed venalitate eius factum arbitror. Unde miror, quia in eos culpam hanc minime vestra excellentia vindicavit. Sed tamen quia hoc miratus sum, memetipsum citius reprehendi. Nam ubi domnus Iustinus consilium prebet, qui pacem cum catholica Aecclesia non habet, ibi non possunt heretici addici.

Preterea sancti Petri apostolorum principis natalicium diem in Romana civitate vos facere velle perhibetis. Et oramus omnipotentem Dominum, ut sua vos misericordia protegat et vota vestra vos implere concedat. Sed predictus vir eloquentissimus peto ut simul veniat; qui si non venerit, a vestris obsequiis recedat: vel certe, si vestra excellentia fortasse emergentibus causis venire nequiverit, ipse autem sanctae Aecclesiae unitati communicet, aut peto, ut vestrorum consiliorum particeps non sit. Bonum virum audio, si pessimi non esset erroris.

De causa vero Maximi, quia importunitatem dulcedinis vestrae iam ferre non possumus, quid decrevimus, Castorio notario suggerente cognoscitis.

Critical apparatus

asic B: pro hominibus. bex piissimas corr. B. cex suggere corr. B.

Translation

Gregory to Callinicus, the Exarch of Italy.

In the midst of what you have announced to me of your victories over the Slavs, know that I have been refreshed with great joy that the bearers of these news, hastening to be joined to the unity of holy Church from the island of Koper, have been sent by your Excellency to the blessed Peter, prince of the apostles. For hereby you will the more prevail over your enemies, if you recall under the yoke of the true Lord those whom you know to be the enemies of God; and you will prosecute your causes among men with all the more effect as with sincere and devout mind you maintain the causes of God.

Now as to your having desired that a copy should be shown to me of the order that has been sent to you for the defense of the schismatic, your to me most sweet Excellency ought to have considered carefully how that, although that order has been elicited, you are still not therein enjoined to repel those who come to the unity of the Church, but only, at this unsettled time, not to compel those who are unwilling to come. Whence it is necessary for you with all speed to inform our most pious Emperors of these things, to the end that they may be aware how that in their times, through the succor of Almighty God and your exertions, schismatics are hastening to return of their own accord.

What I have decided as to the ordering of things in the island of Koper, your Excellency will learn through our most reverend brother and fellow bishop Marinianus. But I would have you know that this has caused me no slight distress; that your majordomo, who took charge of the petition of the bishop who was wishing to return, declared that he had lost it, and that afterwards he was got hold of by the adversaries of the Church: which proceeding, in my opinion, was due not to his neglect but to his venality. Wherefore I wonder that your Excellency has not in any way visited his fault in him. And yet I soon blamed myself for wondering at this, for where the lord Justin gives advice, there heretics cannot be arraigned.

Moreover, you tell us that you wish to keep the anniversary of Peter, prince of the apostles, in the city of Rome. And we pray Almighty God to protect you with His mercy and grant you a fulfilment of your desires. But I beg that the aforesaid most eloquent man may come with you, or that, if he does not come, he may retire from attendance on you. Or certainly, if your Excellency should be unable to come owing to business that may arise, let him either communicate with the unity of holy Church, or I beg that he may not be a sharer of your counsels. For I hear of him as a good man, were he not in most mischievous error.

As to the cause of Maximus, inasmuch as we can no longer stand against the importunity of your sweetness, you will learn from Castor, the notary, what we have determined.

[the translation is based, slightly modified by the editor, on James Barmby, From Nicene and Post-Nicene Fathers, 2nd Series, vol. 13, edited by Philip Schaff and Henry Wace (Buffalo, NY 1898.), revised and edited for New Advent by Kevin Knight, http://www.newadvent.org/fathers/360209009.htm]

Selected Bibliography
Rajko Bratož, "Koprska škofija od prve omembe (599) do srede 8. stoletja," Acta Histriae 9/1 (2001): pp. 37-64
Maurizio Levak, Slaveni vojvode Ivana: Kolonizacija Slavena u Istri u početnom razdoblju franačke uprave (Zagreb 2007), esp. 13-18.
Florin Curta, "The Early Slavs in the Northern and Eastern Adriatic Region: A Critical Approach," Archeologia Medievale 37 (2010): pp. 307-29, esp. pp. 312-12.
Editor's Notes

The letter presents the first written record of Slavic incursions into Istria, officially opening a centuries long period of gradual demographic transformation of the Peninsula into a multiethnic region. The letter forms a part of the following series of primary sources:

1) The letter of Pope Gregory I to Callinicus, the Exarch of Ravenna, dated May of 599, mentioning the victory over the Slavs in a battle fought, most probably, in Istria (the source hereby edited);

2) The letter of Pope Gregory I to Maximus, the Bishop of Salona, mentioning the Slavic incursions into Italy by way of Istria (see the source here);

3) The narrative accounts of early 7th-century Slavic incursions penned by Paul the Deacon in the 8th century (see the sources here and here);

4) The narrative accounts of 7th-century Slavic incursions penned by John the Deacon in the first decades of the 11th century (see the sources here);

5) The narrative account from Liber pontificalis regarding the mission of abbot Martin, sent by Pope John IV to retrieve the relics from Dalmatia and Istria (see the source here).

After the middle of the 7th century, there are no more written testimonies of Slavic presence in Istria until the fateful Plea of Rižana of 804 (see the source here).

The source also features one of the earliest mentions of the Church (that is, the Bishopric) of Koper (insula Capritana = Capris) which officially seceded from the so-called Aquileian or Istrian schism (see more on that here).

How to Cite
First citation: Josip Banic (ed.), Fontes Istrie medievalis, vol. 1: A seculo VI usque ad 803, doc. 599_PGC, fontesistrie.eu/599_PGC (last access: date).
Subsequent citations: FIM, 1: doc. 599_PGC.
Facsimile
Image Source and Info

The images were downloaded from the official webpage of Bibliothèque Nationale de France.

The editor has subsequently inserted red arrows on the folios to mark the parts of the manuscript that refer to this particular letter that is hereby edited.

The images remain under the copyright of their respective institution.