This theoretical chapter discusses the concepts of (historical) legacies, heritage (patrimony), and tradition—key terms which lie at the core of the virulent debates among Balkan historians over national identities and the possession, by virtue of purported bequest from the past, of segments of history—and their relation to history writing in Southeastern Europe. Carrying similar meanings and often used as synonyms in popular parlance, as scholarly (analytical, heuristic) concepts they have parted ways during the last decades, whereby there is a bifurcation between legacy and history, on the one hand, and heritage/patrimony and tradition, on the other. After surveying the applicability and explanatory power of the concept of historical legacies, with a focus on Balkan historiographies, the close filiation between heritage and tradition, and the analytical distinctions between legacy and heritage, the chapter discusses at some length and exemplifies the similarities and permeations between (the production of) heritage/tradition, collective memory, and national history in the Balkan context—interpenetrations bespeaking the mechanisms that ignite and fuel historiographic wars. The last part of this chapter discusses the international legal ramifications of historiographic wars by the example of the international agreements concluded between Greece and Macedonia since the 1990s.