This paper presents a novel dimension in the development of the definite article in Contemporary Standard Bulgarian (CSB). CSB—thanks to its geographical position—participated in numerous areally-based changes that define the Balkan Sprachbund , an area where long-term intense contact amongst speakers of several different languages has resulted in substantial structural convergence (see Joseph 1999). Importantly, CSB, along with Macedonian with which it combines to form the Eastern branch of the South Slavic languages, has several characteristics which set it apart from other Slavic languages, namely the elimination of a nominal case system, the lack of an infinitive, and the development of a definite article. The aim of this paper is to show that the definite article in CSB evolved as a result of both internal (see Dimitrova-Vulchanova & Vulchanov 2009) and external triggers (see Mladenova 2007), namely under pressure from both Romanian and Greek, which led to the gra mmaticalization of the Old Church Slavonic demonstrative pronoun into a definite article. It has often been portrayed in the literature surrounding the Balkan Sprachbund that Greek, although it displays overt definite markers, could not have contributed a postpositive article to the Balkan feature pool (see Lindstedt 2014) given that definite articles are prepositive. Contrary to this view, we highlight a previously undiscussed dimension of complexity in the formation of the definite article in CSB, namely how Greek deter miner spreading could have partially contributed towards the emergence of a postpositive definite article in CSB. Such contact, coupled with adstrate pressures from the north, namely from Romanian, may well have exacerbated an otherwise internal development.