In medieval Serbia a social group known as "Vlachs" (Serbian: Власи / Vlasi) existed. While the term Vlachs had more meaning, primarily denote the inhabitants of Aromanian origin and also dependent shepherds in the medieval Serbian state.

Vlachs are first mentioned in 1198 living in the area between Timok and Morava which was later annexed by the Serbians in 1292, by Stefan Milutin. Also, Stefan Milutin in a deed of a gift to the monastery of Hilandar demanded that Vlachs coming to the kingdom must belong to the Holy Church, which also applied to foreigners as well as to dependent peasants.^[4] Serbia of 12th and 13th century with Greek-Orthodox population received a growing number of Vlach population which migrated from Dalmatian coast, Epirus, or Thessalonica and from Bulgaria after Kaliman Asen II was deposed and expelled. Vlachs in the time of Stefan Dečanski and Stefan Dušan provided the Serbian state with excellent horses for the army. The Serbian peasants and the Vlach herdsmen had disagreements with each other especially because Vlach destruction of agricultural land, forcing Serbian State to regulate the wandering shepherds and to protect its own Slav peasants with draconic laws. After that many Vlachs migrated from Serbia to Wallachia or Transylvania^[5]

Northwest of Niš there are records of Vlachs in 1382 and in Kučevo area from 1428. Suleiman the Magnificent in 1521 made a law (Canun name) for Vlachs living between Braničevo and Vidin.^[6]

The vlasi (власи) or pastiri (пастири) are primarily the inhabitants of Aromanian origin and also dependent shepherds in the medieval Serbian state, part of the sebri social class.^[7][8] The multitude and likely prevalence of Vlachs (Romanized remnants) among the shepherds made the term "Vlachs" a synonym for shepherds, similarly as the term Srbljin was sporadically used for farmers.^[9] The status of the vlasi was basically equal to the meropsi.^[9]

The first mention of "Vlachs" in Serbian historical sources is the Hilandar founding charter (1198–99) by Stefan Nemanja. 170 Vlach families were mentioned in the Prizren area,^[10] granted together with villages and churches. Romance names were identified through de Radu i Đurđa.^[11] Nemanja's son, Stefan the First-Crowned, granted the Žiča monastery with 200 Vlach families from the Prokletije mountain, near Peć, Kosovo.^[11] In 1220, king Stefan proclaimed that all Vlachs of his kingdom belonged to the Eparchy of Žiča.^[11] Vlach counts (comes catuni or catunarius) were mentioned in Hvosno in 1220, 1282–98 and 1302–09.^[11] Crusader chronicles describe encounters with Vlachs in various parts of modern Serbia in the 12th and 13th centuries.^[11] King Stefan Uroš I of Serbia granted the Hilandar monastery with another 30 Vlach families from the Drim river.^[11] In the grant (around 1280) by his wife and queen, Helen of Anjou, which confirmed the grant given by Stefan Vladislav to the Vranjina monastery, the Vlachs are separately mentioned, along with Arbanasi (Albanians), Latins and Serbs.^[11] King Stefan Milutin's charter to the Banjska monastery granted it with six katuns (highland hamlets), and also made the first mention of the "Vlach law" (zakon Vlahom).^[11] In 1330, King Stefan Dečanski granted the Visoki Dečani monastery with pasture land along with Vlach and Albanian katuns around Drim and Lim rivers of whom had to carry salt and provide serf labour for the monastery.^[11][12][13] Three of the deeds of gift written by Stefan Dušan mention Vlachs together with Serbs where they are mentioned separately ("Vlachs as well as Serbs").^[14] Granting monasteries with Vlachs continued during the reign of Emperor Stefan Uroš V (1355–71), in his charter as members of the Church of St. Nicholas in Hvosno, and 30 Vlach families as servants of Gračanica monastery, Kosovo.^[11]

According to Croatian-Albanian historian Zef Mirdita, despite the fact that the "Vlach" exonym partially meant shepherds as a socio-professional category (regardless of ethnos), the individuality and identity of the Vlachs are seen in the Banjska and Dečani charters, as well as in Dušan's Code (1349).^[11] Therein is included a prohibition of intermarriage between Serbs and Vlachs,^[11] while after Emperor Dušan conquered a large part of southeast Europe (including Macedonia, Epirus and Thessaly, that is Great Vlachia, and Albania, with significant Vlach population) he clearly differs Vlachs from Serbs and Albanians.^[11] An article provides that in the case of conflict between villagers it is punishable with a fine of 50 perper, while among Vlachs and Arbanasi of 100 perpers.^[11] Another article, on the Vlachs and Arbanasi, prohibits the overnight stay by other shepherds in villages of Vlachs or Arbanasi, and in case they did, have to pay for the amount their herds graze.^[11] The protection of Slav peasants by the Dušan's Code forced many Vlachs to migrate from Serbia.^[5] Dušan's charters of the Monastery of the Holy Archangels and Hilandar mention duties of Vlachs regarding shepherding and annual giving away of either sheep, two horses for the purpose of transporting salt and other monastery needs, mowing hay, compensation in 30 perpers or construction workers.^[11]

The medieval Vlachs in the Balkans had hybrid names, evidenting intermarriage with the Slavs.^[15]

According to Sima Ćirković, documents from 13th to the 15th century show that the Vlachs were considered by the Serbs as "others" i.e. different from themselves, while documentation on that particular issue is scarce so it is very difficult to conclude how the difference is perceived.^[16] It is also noticeable that the name "Vlach" in medieval sources has the same rank as the name "Greek", "Serb" or "Latin".^[17] According to Andre Du Nay, written records from Serbia in the 13th to 15th century mention Albanians, Vlachs, but also Serbians living in the same areas, although historical records from earlier periods do not exist certain circumstances indicate that the Vlacho–Albanian symbiosis stems from antiquity.^[18]

• Morlachs
• Vlach law
• Vlachs in medieval Bosnia
• Vlachs of Croatia
• Vlach (Ottoman social class)