The integration of traditional and modern linguistics as well as diachrony and synchrony is the hallmark of an influential trend in contemporary research on language. It is documented in the present collection of 21 new papers on the history and structure of the sounds and other (sub-) systems of human languages, sharing the common reference point of Theo Vennemann, a leading figure in the above-mentioned trend, whom the authors want to honor with this Festschrift.