In the Balkan Slavic languages, whose dialects actually form a dialectal continuum, clitic doubling shows gradual variation along a vertical north-south axis and a horizontal east-west axis. On the north-south axis, there is variation with respect to the categories that can be clitic-doubled. On the east-west axis languages/dialects vary with respect to the conditions on clitic doubling, with almost total dependence on discourse factors in the easternmost dialects in the area and remarkable dependence on grammatical factors in the westernmost ones. In the majority of the Macedonian dialects discourse factors do not play any role and all definite direct objects and all specific indirect objects are clitic doubled. In Western Macedonia, the vertical north-south axis and the horizontal east-west axis along which clitic doubling variation in Balkan Slavic moves, intersect, so that in the Western Macedonian dialects, as well as in Standard Macedonian, which is based on the West-Central dialects, clitic doubling is obligatory with all definite direct and all specific indirect objects. In the case of indirect objects, the specificity effect does not always hold; even non-articled NPs, which are never specific, can sometimes be clitic doubled. Accordingly, in Western and Standard Macedonian the doubling clitic is becoming a mere case marker of the object it doubles. In Aromanian and Megleno-Romanian, two Romance Balkan languages which are in close contact with the Western Macedonian dialects, the conditions for clitic doubling are analogous to those in Macedonian. This fact leads to the conclusion that the grammaticalization of the doubling clitic is an areal phenomenon.