Language rifts in the Balkans are endemic and have long been both a symptom of ethnic animosity and a cause for inflaming it. But the break-up of the Serbo-Croatian language into four languages on the path towards mutual unintelligibility within a decade is, by any previous standard of linguistic behaviour, extraordinary. Robert Greenberg describes how it happened. Basing his account on first-hand observations in the region before and since the communist demise, he evokes the drama and emotional discord as different factions sought to exploit, prevent, exacerbate, accelerate or just make sense of the chaotic and unpredictable language situation. His fascinating account offers insights into the nature of language change and the relation between language and identity. It also provides a uniquely vivid perspective on nationalism and identity politics in the former Yugoslavia.