The 1376 and 1454 documents by Republic of Ragusa about trade with Bosnian lands mention Vlachi et Bosgnani. In the 1418 document by Grgur Nikolić, Vlachs, Serbs and Ragusians are clearly distinguished. In the 14th century documents, they are treated as shepherds from mountains that separate Croatia and Bosnia. It is argued that some group of Vlachs in the 14th century migrated to Zagora and Cetina county in Croatia, followed by the sudden appearance of stećaks in the territory they lived. In 1436, on the Cetina are mentioned Vlachs, Croats and Serbs which were part of Count Ivan Frankopan’s estate. At a time of social unrest, the Vlachs often fled to the area of Ragusa or Kotor, served in the military of Ragusa during the Ottoman threat, and when most of Herzegovina was occupied by the Ottomans by 1472, once again fled to Ragusan territory. Some data of historic documents show that a part of Vlachs were Bogomils and they largely contributed to the spread of this sect. According to Sima Ćirković, ethnicity's which appear in the medieval texts from Bosnia include names such as "Bošnjanin", "Vlach", "Latinin" and "Serb". Ottoman rule Ottomans in Bosnia and Herzegovina, following the example of katuns, organized filurîci eflakan (Vlach filurîci) according to "Vlach model" in Smederevo, Vidin and Braničevo. From them was collected taxes baduhava eflakan, or rusum eflak, mostly in the form of sheep or goats, as well gold currency. In the defters of the 1470s and 1480s in Central and North-Central Bosnia, around Visoko and Maglaj, roughly 800 Vlachs arrived accompanied by two Orthodox priests. With war and plagues, and as Catholics fled, the repopulation of Bosnia from Herzegovina and Serbia was of high interest for the Ottomans for their military activities. Benedikt Kuripečič in the 16th century noted that Bosnia is inhabited by three peoples; (Muslim) Turks, (Catholic) Bosnians and (Orthodox) Serbs "who call themselves Vlachs... They came from Smederevo and Belgrade". According to Noel Malcolm in these migrations also participated Serbs and Herzegovinians who were not Vlachs. Since Vlachs weren't paid for military activity by the Ottomans they were permitted to plunder enemy territory, and became known as martolos or voynuk. Their military activity earned them special tax privileges. In the late 15th century at least 35,000 Vlachs lived in Herzegovina, while in the 16th century 82,692 Vlach households lived in the Smederevo region in Serbia. Within the territories