According to Kingsley Garland Jayne: The great Slavonic migration into Illyria, which wrought a complete change in the fortunes of Dalmatia, took place in the first half of the 7th century.
This opposition was intensified by the schism between Eastern and Western Christianity (1054), the Slavs as a rule preferring the Orthodox or sometimes the Bogomil creed, while the Italians were firmly attached to the Papacy.
To such a division of population may be attributed the two dominant characteristics of local history—the total absence of national as distinguished from civic life, and the remarkable development of art, science and literature.
Bosnia, Servia and Bulgaria had each its period of national greatness, but remained intellectually backward; Dalmatia failed ever to attain political or racial unity, but the Dalmatian city-states, isolated and compelled to look to Italy for support, shared perforce in the march of Italian civilization.
[3]Indeed, in the Early Medieval period, Byzantine Dalmatia was ravaged by an Avar-Slavic invasion (more specifically the Croats per Thomas the Archdeacon[4]) that destroyed its capital, Salona, in 639 AD.
[9] Around 950 AD, as the Dalmatian city-states gradually lost all protection by Byzantium, being unable to unite in a defensive league hindered by their internal dissensions, they had to turn to Venice for support.
[10][11] The Venetians, to whom the Dalmatians were already bound by language and culture, could afford to concede liberal terms as its main goal was to prevent the development of any dangerous political or commercial competitor on the eastern Adriatic.
The Dalmatian cities might elect their own chief magistrate, bishop, and judges; their Roman law remained valid, and they were even permitted to conclude separate alliances.
Speakers lived mainly in the coastal towns of Jadera (Zadar), Tragurium (Trogir), Spalatum[12] (Split), Ragusium (Dubrovnik), and also on the islands of Curicta (Krk), Crepsa (Cres), and Arba (Rab).
[14] His language[15] was studied by the scholar Matteo Bartoli, himself a native of nearby Istria, who visited Udaina in 1897 and wrote down approximately 2,800 words, stories, and accounts of his life.
Bartoli wrote in Italian and published a translation in German (Das Dalmatische) in 1906; this book is considered the first on ethnic minority disappearance in world literature.
[citation needed] Historian Johannes Lucius included Flumen (now Rijeka) and Sebenico (now Šibenik) after the year 1000, when Venice started to take control of the region, in the Dalmatian Pale.
[citation needed] Indeed, Flumen was the former Roman Tarsatica: a small, fortified city under the Italian Aquileia (and Pola) bishops, enclosed within the town walls which had several defense towers.
South of the ancient Roman municipium of Burnum, which disappeared after its heyday in the 2nd century,[16][better source needed] the town of Šibenik or Sebenico was founded by the Croats.
Gradually however the Sebenzani became Latinized, and in later ages, the city was described by Fortis as next to Zara the best built-in Dalmatia, and inhabited by the greatest number of noble families, as far removed from the barbarous manners of ancient pirates as their houses are unlike the former cottages or sibice; and the same writer tells us that in the sixteenth century the arts and sciences flourished in this city more than in any other of Dalmatia.Lucius wrote even that Pagus (the Venetian Pago, now called Pag) had municipal autonomy and was virtually independent for centuries around the year 1000.