Joseph H. Greenberg is a towering figure in late twentieth century linguistics. His major contributions in the field have been in the area of typology and universals, virtually launched by his paper on word order universals, and in diachronic linguistics. The major thrust of Greenberg's work in the past three decades has been in the fusion of these two approaches to linguistic explanation into one, diachronic typology, the cross-linguistic analysis of languages as dynamic systems.This volume honors Greenberg on the occasion of his 75th birthday. It opens with an introduction discussing Greenberg's work at length and a full bibliography of his publications. It contains ten papers in typology, diachronic theory and diachronic typology by some of the leading linguists working in the research tradition inspired by Greenberg's work.