The eastern borders of the province of Istria (and the Kingdom of Italy / Holy Roman Empire) according to the 10th-century work customarily titled De administrando imperio and ascribed to Eastern Roman Emperor Constantine VII Porphyrogenitus.
Διήγησις περὶ τοῦ θέματος Δελματίας <XXX>a
ʹΕκ παλαιοῦ τοίνυν ἡ Δελματία τὴν ἀρχὴν μὲν εἶχεν ἀπὸ τῶν συνόρων Δαρραχίου, ἤγουν ἀπὸ ʹΑντιβάρεως, καὶ παρετείνετο μὲν μέχρι τῶν τῆς ʹΙστρίας ὀρῶν, ἐπλατύνετο δὲ μέχρι τοῦ Δανουβίου ποταμοῦ.
ʹΑπὸ δὲ τῆς Ζεντίνας τοῦ ποταμοῦ ἄπχεται ἡ χώρα Χπωβατίας, καὶ παρεκτείνεται πρὸς μὲν τὴν παραθαλασσίαν πέχρι τῶν συνόρων ʹΙστρίας, ἤγουν τοῦ κάστρου ʹΑλβούνου, πρὸς δὲ τὰ ὀρεινὰ καὶ ὑπέρκειται μέχρι τινὸς τῷ θέματι ʹΙστρίας, πλησιάζει δὲ πρὸς τὴν Τζέντινα καὶ τὴν Χλέβενα τῇ χώπᾳ Σερβλίας.
a) add. al. man. in marg. dex. B.
Capitulum XXX: De Themate Dalmatiae narratio
Antiquitus igitur Dalmatia incipiebat a confiniis Dyrrachii, sive ab Antibari, et ad Istriae montes usque pertingebat; in latitudine vero ab Danubium flumen se extendebat.
A Zentina autem fluvio Chrobatia incipit extenditurque versus mare ad Istriae usque confinia, sive Albunum urbem; versus montana aliquatenus etiam super Istriae Thema excurrit, ac versus Tzentina et Chlebena Serviae regionem attingit.
[Anselmo Banduri (trans.), “De administrando imperio,” in Imperium orientale sive antiquitates Constantinopolitanae, vol. 1 (Venice 1729), pp. 77, 79.]
30: Story of the Province of Dalmatia
In olden times, therefore, Dalmatia used to start at the confines of Durrës, or Bar, and used to extend as far as the mountains of Istria and spread out as far as the River Danube.
From the River Cetina begins the country of Croatia and stretches along on the side of the coast as far as the frontiers of Istria, that is, to the city of Labin, and on the side of the mountain country it encroaches some way upon the province of Istria, and at Cetina and Livno becomes neighbor to the country of Serbia.
[The translation, modified by the editor so that the toponyms match present-day place names, stems from Romilly James Heald Jenkins (trans.), De administrando imperio, ed. Gyula Moravcsik, Corpus fontium historiae Byzantinae 1 (Washington D.C. 1967), pp. 139, 141, 145, 147.]
This chapter, written most probably in the final quarter of the 10th century as a “correction” of chapters 29 and 31 (on that see Bury’s and Ančić’s articles cited above), corroborates the thesis, famously argued by Bernardo Benussi, that the Učka mountain range was indeed the natural and political border separating Istria from Liburnia, thus also separating the Holy Roman Empire from the Kingdom of Croatia-Dalmatia.
That the “mountains” separate the two regions was also argued by the Anonymous Ravenna Cosmographer – see the edition of the relevant chapters here.
Furthermore, the towns of Labin and Plomin, to the east of the Raša but to the west of the Učka, were parts of the County of Istria and did not belong to the Regnum Croatie et Dalmatie, as demonstrated by the donation charter issued by Emperor Henry II in 1012 to the Patriarchate of Aquileia – edited here.
Benussi, however, also argued that the borders of Istria, and thus the Kingdom of Italy, moved from the river Raša to the river Rječina, already in the age of Emperor Constantine the Great.
Benussi based this argument on the famous 14th-century chronicle penned by Andrea Dandolo which contains the following chapter:
“Nam Caçanus, Avarum rex, cum Sirmium opulentem civitatem iam invasisset, usque ad muros longos pervenit, de quibus Comenciolus pretor missus victoriam optinuit. Hii enim muri dividunt Greciam et Traciam a solo barbarico, incipientes in finibus Ystrie ab urbe Tarsia, protendentes ultra terminos urbis Constantinopolitane.”
[Andrea Dandolo, Cronica per extensum descripta, ed. Ester Pastorello (Bologna 1942), p. 86]
For Benussi, this city of Tarsia was equated with the river Rječina (how?), and this was all the evidence he needed to reach the following conclusion:
“Dalle surriferite parole del Dandolo si deve ammettere che il confine orientale dell’Istria, durante l’impero, venisse spostato e trasferito dall’Arsia al fiume prossimo, vale a dire alla Tarsia, l’odierna Reca, includendo così nell’Istria un lembo della Liburnia.” (Benussi, Nel medio evo, p. 58).
This argument is untenable, and it stemmed primarily from the desire of 19th-century Italian nationalists to “prove” the Italianity of Rijeka (on that see Mattia Vitelli Casella, “Il confine nord-orientale dell’Italia romana negli studi tra XIX e XX secolo,” Futuro Classico 5 (2019): 242–71).
Namely, already in 1919 Carlo Maranelli and Gaetano Salvemini voiced their disagreement with this Benussi’s claim:
“Ma a parte ogni possibile contestazione sulla interpretazione, che il Benussi dà alle parole ‘urbs Tarsia’, a parte cioè ogni possibile discussione sulla localizzazione del muro, di cui parla il Dandolo nel secolo XIV, e sulla sua identità col muro, i cui resti si vedono a Fiume, – quale valore può mai avere una cronaca del secolo XIV che parla di fatti del secolo VI, per attestarci uno spostamento di confine, che sarebbe avvenuto al tempo del basso impero, mentre nessun’altra fonte ci dà una notizia di questo genere?” (Maranelli–Salvemini, cited above, pp. 28-29).
The argument was further deconstructed and demonstrated utterly untenable by Lujo Margetić, who showed that Dandolo’s passage in question is based upon Historia Romana penned by Landolfus Sagax, namely, book 19, chaps. 7-8:
“Eodemque anno [i.e. 577] legatione funguntur Avares ad imperatorem Mauricium, qui ante breve tempus Syrmium subegerant [om.] ... Porro chaianus Avarum pacem solvere festinabat, nam Sclavinorum gentes contra Thracem armavit, qui pervenerunt usque ad Longos Muros multum facientes excidium. At imperator (om.) Comentiolum ducem ordinans et armans contra barbaros misit. Qui insperate in barbaros ruens copiosas multitudines interfecit hosque pepulit.”
[Landulfus Saxas, Historia Romana, ed. Amadeo Crivelucci, 2 vols, Fonti per la storia d’Italia 50 (Turin 1968), here vol. 1, pp. 68–69]
Thus, Dandolo simply added the “explanation” regarding the “long walls” – which, by the way, protected Constantinople from the west and had absolutely nothing to do with either Istria or the area around Trsat –, most probably mixing up Ister, as in the River Ister/Danube with Istria,(on this false cognation see this document), and inventing the “mysterious city of Tarsia that, perhaps, entered the explanation out of Dandolo’s desire for ‘meticulousness’ and a desire to impress the uninformed reader.” (Margetić, cited above, pp. 62–65, quotations on p. 65).
The area between the Učka mountain range and the river Rječina would not stay under the Kingdom of Croatia-Dalmatia for long (see the description of the region penned by Al-Idrisi in the middle of the 12th century – to be edited here presently), but even after the area’s incorporation into the Holy Roman Empire, as part of the temporal jurisdictions of the patriarchs of Aquileia, the microregion in question would not be considered as part of Istria, but as Liburnia, Meran(ia) or even Croatia (see this source).
Thus, it must be concluded that throughout the Middle Ages the eastern border of the region of Istria was the Učka mountain range, with the river Raša occasionally cited as the region’s border due to the influence of classical geography on medieval authors (see Maranelli–Salvemini, cited above, pp. 31–38 for a rich selection of medieval and early modern authors corroborating this thesis).
The facsimiles of ms. hereby dubbed B stem from the official web pages of Bibliothèque nationale de France where they are freely available for consultation.
The editor has subsequently inserted red lines and arrows simply to denote the parts of the manuscript that are hereby edited.
All images remain under the copyright of their respective institutions.