When the neolatin population of Roman Dalmatia was massacred by the Avars and Slavs, the survivors were divided in two groups: those in the coastal areas who took refuge in the islands with a few walled cities like Ragusa, Spalato and Zara (now called Dubrovnik, Split and Zadar) and those who moved to the mountains & highlands where they lived a pastoral life.
The first (more civilized) were called Dalmatians while the second Vlachs. In Dalmatia the neolatin Dalmatians after some centuries were assimilated by the Italians of the Republic of Venice: by the fourteenth century they practically disappeared in a process of "italianization" (the last was Antonio Udaina, who was the last speaker of the Dalmatian language when he died in 1898-according to the linguist Matteo Bartoli).
Indeed the Vlachs moved into central coastal Dalmatia, controlled by the Republic of Venice, initially in the 1300s, when the Ottoman invasion of the Balkans started.
They were called by the Venetians with the name "Morlacchi" (or "Mor(ava-va)lacchi"; in english: "Vlachs from Morava river" or "Morlaks") and came mainly from the Bosnia-Erzegovina's "Romanija" and the Serbia's "Stari Vlah", but some of them even from Montenegro and Kossovo/Albania. Most of them spoke their original neolatin language, but with many serbo-croatian words and sentences. Indeed one sixteenth-century Venetian writer described the Vlachs of the Dalmatian hinterland as speaking "Latin, though in a corrupted form" (some shepherds in those mountains were still using Vlach counting-words as recently as 1985).
Cristian Luca wrote -in his book: The Vlachs/Morlaks in the Hinterlands of Traù and Sebenico- that "the Romanic origin and the linguistic and ethnic communion between the Vlachs and the Romanians living to the north of the Danube are well known, so that it is not necessary to bring into discussion the theories, which are devoid of any scientific basis, which consider the Vlachs/Morlaks/Aromanians as Greeks or Slavs. In the case of the Morlaks from Dalmatia, it is true that they were gradually slavicized, although the process which led to their assimilation into the Croatian population lasted for several centuries".
Unlike the population of Roman towns and villages in the Balkans that disappeared after the migration of the Slavs, the nomadic/semi-nomadic Vlachs survived the Slavic massacres as an individual entity. In the course of time, however, under the influence of a Slavic environment the outnumbered Vlachs started to Slavicise and at first, became bilingual after the IX-X century. By contrast, some of the Slavic population in some areas adopted the transhumant life-style of the Vlachs and mixed with the Vlachs in some areas, like in Rascia/Arsia (originating the first state of the Serbs).
Cristian Luca also wrote that from the 15th century, the Vlachs in Dalmatia were also called "Morlaks", and from about the first decades of the 18th century, they became also named "Aromanians" or "Macedoromanians", belonging, from an ethno-linguistic point of view, to the Eastern Romanity, being speakers of a Romanian dialect. As mentioned above, the Vlachs settled in Dalmatia and then in Bosnia, mainly from the beginning 14th century, and came from the mountainous areas of the central Balkan Peninsula. They were scattered – in small, closed communities, united in a strong solidarity which arose from dealing exclusively in long term transhumant sheep breeding – in different parts of the South-Danubian area. Their presence was frequently attested to in sources from the 12th-18th centuries in Albania, Macedonia, Bulgaria, Serbia, Montenegro, Bosnia, Herzegovina, Croatia and mainland Greece (even in several Greek islands).
Although traditionally devoted to transhumant sheep breeding, there is also early documentary evidence mentions their presence in the Balkan Peninsula, and their excellent enterprising ingenuity in engaging in the caravan trade. By the first decades of the 17th century, they had established themselves as one of the most important groups of trading middlemen between the Italian Peninsula and Eastern Europe.
The migration of several groups of Vlachs/Morlaks from inside the Balkan Peninsula towards the coast of Venetian Dalmatia (Venetian Dalmatia on English Wikipedia) was also determined by the phenomenon of transhumance, which was the main occupation of this Romanic population. In it, sheep were bred in open areas, in the pastures of the high mountain ranges of the Balkan region. Transhumant sheep breeding imposed seasonal rhythmic cycles on the movement of flocks. Thus, as a result of their search for areas with a milder climate to settle down for the winter, the Vlach shepherds begin arrived on the coasts of central Dalmatia in the 14th century, where their presence was frequently reported in contemporary sources. In this coastal region they found pastures all along the winter, so that many decided to settle in the hinterland of urban centers under Venetian domination. In the subsequent centuries, some of them divided their existence between the Dinaric Alps, where they were kept their herds from spring until autumn, and these Dalmatian regions.
A situation of this kind can be found in the 16th century in the hinterlands of the towns of Traù (Trogir in Serbo-Croatian) and Sebenico (Šibenik in Serbo-Croatian), which had been part of Venice’s "Stato da Mar" since the second decade of the 15th century. Sebenico, is located in central Dalmatia, at the point where the Krka river flows into the Adriatic Sea. It is situated at about 30 km west of Traù. However both ports were economically eclipsed in importance by another Venetian port, Spalato (Split), the main transit center which coordinated the trade on the Balkan land routes between the Serenissima and Eastern Europe. Sebenico, through its strategic position and the military functions of its port, had an important role in defending the Venetian possessions in Dalmatia. Therefore Serenissima’s government decided to build a fortification named St.Michael, on the heights that dominated the city. In its turn, Traù was mainly protected by its natural location, the urban settlement being built on two islands lying in front of the central Dalmatian coast.
In 1774, when abbot Alberto Fortis made his famous journey in Dalmatia, the Vlachs/Morlaks from the settlements on the Krka river, including those in the hinterland of the town of Sebenico, were not yet slavicized, although the Venetian author inaccurately assigned them this origin.
Prior to Fortis, Giovanni Lucio, quoted by Jacob Spon and George Wheler, mentioned the Romanic origin of the Morlaks of Dalmatia and their ethnic and linguistic affinity with the Wallachians from the Romanian Principalities.
Venetian sources from the second half of the 16th century recorded the earlier stages of the Vlachs/Morlaks penetration and establishment into the hinterland of the town of Traù. In 1562 the inhabitants of the town of Trau (the old Tragurium) which belonged to Serenissima’s "Stato da Mar" mentioned the seasonal presence of the Vlachs/Morlaks in the area, where they had started arriving in 1525 to find winter shelter for their herds: in less than a decade, by 1531, the Vlachs/Morlaks had steadfastly settled down in the territory of the town of Traù, near the border with the Ottoman province of Bosnia.
The newcomers founded several rural settlements and began to grow grain on the neighbouring arable lands. Finally, in 1550 no less than 11 settlements inhabited by the Vlachs/Morlaks were recorded. They were located in Veneto-Ottoman border territory, in the area lying between Traù and Sebenico: Labin,Opor, Trilogue (Trolokve), Radosich (Radošić), Podine, Vrsno, Liubitoviţa(Ljubitovica), Lepeniţa (Lepenica), Prapatnica, Suchidol (Suhi Dolac) and Sitno.
The Vlach/Morlak settlements from the hinterland of Traù were already a demographic, economic and administrative certainty in 1626, when another morlak settlement was done: in the area of the port-town of Sebenico a gradual penetration of the Vlach/Morlak shepherds, merchants and carters, was also recorded. The latter were also active at Zara (Zadar) and Traù, but without having settled down in the Trau hinterland, where the establishments mentioned earlier had been founded by the shepherds and their families.
Indeed during the first years of the second half of the 16th century, the Vlachs/Morlaks were exploiting, together with the Venetian subjects of Sebenico, several mills built on the Krka river, near Scardona (Skradin). The Vlachs/Morlaks penetrated only temporarily into the territory of the town of Sebenico, without attempting to establish durable settlements in the area under the jurisdiction of the Serenissima and recognized as such by the Sultan Süleyman I Kanûn.
The Bunjevci, a group of Vlachs who presumably originated from western Herzegovina, migrated to venetian Dalmatia in the early 1400s, and from there to Lika and Bačka (actual northern Serbia) in the 16th and 17th century. They were catholic "Vlasi", who escaped from the Ottoman invasions and slowly were fully assimilated by the Croats.
The Bunjevci's roots were in middle-ages Bosnia-Erzegovina, a country with a majority of inhabitants speaking a neolatin language before the year 1000 AD (see map above).