Doctoral Dissertation Serbia, Bulgaria and Tatars in the Second Half of the Thirteenth Century deals with two parallel historiographical issues. The former is Serbian-Bulgarian relations during this epoch; the latter is Mongol (Tatar) impact on Southeastern Europe in the proposed timeframe. These two topics are mutually inseparable. The first is impossible to explain without taking the latter into account, while the second is, in turn, illuminated from multiple perspectives by the first. Chronologically, the research starts with the Mongol Invasion of Europe (1241- 1242), which left deep traces of destruction and caused a series of migrations. It finishes with inner conflicts among the Tatars in the Black Sea steppes, which brought changes in the character of their influence and led to a new mass settlement of nomadic populations south of the Danube. In the Balkan frameworks, this epoch began with the death of Bulgarian ruler John Asen II (1218-1241); it ended with an attempt to create a personal union between the two South Slavic states and with king Milutin’s agreement with Byzantium in 1299, thereby announcing the hegemony of the Nemanjić state in the region. The dissertation is based upon a wide range of narrative (Byzantine, Latin, Oriental, Slavic and other writers), documentary (sharters of Popes, Hungarian, Serbian and Bulgarian rulers, material from the Angevin archives), and archaeological sources. Main focus is devoted to political aspects; they are, however, closely intertwined with the military, social and geographical aspects. Structurally, the dissertation is divided into Introductory remarks, six chapters and Conclusion. Introductory remarks provide an overview of the sources and literature, review of the regional geography and terminology used in the text. In the first chapter, the course of events during Mongol invasion of Europe (1241-1242) is presented, as well as its consequences. The second section deals with the establishment of Mongol state in the Black Sea steppes (so-called Golden Horde), and its influence on the Balkan countries in mid Thirteenth century. The next chapter is devoted to the analysis of the relations between Serbia and Bulgaria, internal and external factors that shaped their position. The fourth part is dedicated to the rise of Nogai and his career, while the next one is focused upon his impact on Bulgaria and Serbia. The final chapter deals with his legacy, envisaged through emigration of nomadic Alans and Tatars, close relations between Serbian state and northwestern Bulgarian lands, as well as joint Serbian, Bulgarian and Tatar military activities against Hungary, at the beginning of the Fourteenth Century. The conducted researches solve several chronological issues (such as the time of Nogai’s establishment on the Lower Danube, date of marriage between king Milutin and Hungarian princess Elizabeth, inclusion of Braničevo into the state of king Dragutin, etc.). They reveal groundlesness of some of the established hypotheses in historiography (e.g. the hostage status of Bulgarian Prince Theodore Svetoslav in the Nogai’s lands). Also, it has been shown that: harmonious Bulgarian-Serbian relations grew into a de facto military and political alliance in 1284; a decade later, Serbia became a dependant of the Tatar state formed on the Lower Danube, although for a short time; the ties between Serbia and northwestern Bulgarian lands, formed in the late Thirteenth century under Nogai’s patronage, outlived him for another two decades. Doktorska disertacija Srbija, Bugarska i Tatari u drugoj polovini XIII veka paralelno posmatra dva niza istoriografskih pitanja. Prvi se odnosi na srpsko-bugarske odnose tokom pomenute epohe, a drugi na mongolski (tatarski) uticaj na jugoistočnu Evropu. Ove dve teme stoje u neraskidivoj vezi: prvu je nemoguće obuhvatiti bez druge, a druga je osvetljena iz više perspektiva zahvaljujući prvoj. Gornju hronološku granicu istraživanja predstavlja prodor Mongola na Zapad (1241-1242), koji je ostavio duboke tragove razaranja i izazvao niz migratornih kretanja. Donju čine unutrašnji sukobi epskih proporcija među Tatarima u crnomorskim stepama, koji su doveli do promene karaktera njihovog uticaja, kao i do novog masovnog naseljavanja nomadskih populacija južno od Dunava. Ova epoha je u balkanskim okvirima započela smrću bugarskog vladara Ivana Asena II (1218-1241), a završila se pokušajem stvaranja personalne unije dveju država Južnih Slovena i sporazumom kralja Milutina sa Vizantijom 1299. godine, čime je najavljena hegemonija države Nemanjića u regionu. Teza je zasnovana na širokom spektru narativnih (vizantijski, latinski, orijentalni, slovenski i drugi pisci), dokumentarnih (povelje papa, ugarskih, srpskih i bugarskih vladara, građa iz anžujskih arhiva) i arheoloških izvora. Okosnicu istraživanja čine politički aspekti, ali su oni neraskidivo isprepletani sa vojnim, geografskim i društvenim. Teza je strukturalno podeljena na Uvodne primedbe, šest poglavlja i Zaključna razmatranja. U Uvodnim primedbama dat je pregled izvora i literature, osvrt na geografiju regiona i terminološke napomene. U prvom poglavlju je predstavljen tok mongolske invazije i njene posledice (1241-1242). Drugo se bavi obrazovanjem mongolske države u Crnomorskim stepama (tzv. Zlatna horda) i njenim uticajem na balkanske zemlje sredinom XIII veka. Sledeća celina je posvećena analizi srpsko-bugarskih odnosa, kao i unutrašnjim i spoljnim činiocima koji su oblikovali njihov međunarodni položaj. Četvrto poglavlje je okrenuto usponu i aktivnostima mongolskog velikaša Nogaja, a peto se bavi njegovim uticajem na prilike u Bugarskoj i Srbiji. U poslednjem poglavlju je analizirano nasleđe Nogajeve epohe u jugoistočnoj Evropi, kroz emigraciju nomadskih Alana i Tatara, bliske odnose srpske države i severozapadnih bugarskih zemalja, kao i zajedničko srpsko-bugarsko-tatarsko delovanje protiv Ugarske početkom XIV veka. Sprovedena istraživanja rešavaju više hronoloških nepoznanica (vreme ustoličenja Nogaja na donjem Dunavu, datovanje braka kralja Milutina i ugarske princeze Jelisavete, pripajanje Braničeva državi kralja Dragutina, itd.) i otkrivaju neosnovanost nekih ustaljenih hipoteza u nauci (npr. talaštvo Teodora Svetoslava u Nogajevim zemljama). Osim toga, istraživanja pokazuju da su do tada skladni bugarsko-srpski odnosi 1284. godine prerasli u faktički vojni i politički savez, zatim da je Srbija deceniju kasnije na kratko postala u punom smislu vazal tatarske državne tvorevine obrazovane na donjem Dunavu, kao i da su bliske veze između Srbije i severozapadnih bugarskih zemalja, obrazovane krajem XIII veka pod Nogajevim pokroviteljstvom, nadživele ovog mongolskog velikaša pune dve decenije.