The present paper is concerned with the formal and functional development of the analytic past, i.e. l-participle + auxiliary ‘to be’, in North Slavic (including Slovene) and Balkan Slavic. While in the former languages, the analytic past has developed into a narrative preterit, it is generally assumed to have kept its perfect semantics and additionally have acquired renarrative and evidential functions in Balkan Slavic. These functions are related to the omission of the auxiliary in the 3rd person. The variation in the usage of the auxiliary, in turn, is interpreted as underlying distinct morphological paradigms – perfect and renarrative – and hence as indicating a different path of development than observed for the rest of Slavic. Upon closer inspection, however, the development of these forms might have proceeded less differently in both language groups than traditionally assumed. This is suggested by the ‘auxiliary variation’ in colloquial Serbian and western Serbian dialects. Exhibiting functional similarities with both, Serbian is located at the junction between North and Balkan Slavic.