ABSTRACT In the history of West Germanic, the order of verbal heads and their complements has been extremely variable. Not only has the direction of government switched from leftward to rightward in two of them (English and Yiddish), but the frequency of deviations from strict head final order has varied substantially over time. In this research, we intend to investigate this variation and change by undertaking a detailed comparison of English, German and Yiddish. We will use a two-pronged approach: (1) we will attempt to clarify the grammatical character of the variation by comparative structural analysis, and (2) we will apply quantitative methods to specify the factors governing the variation and to trace the time course of secular trends in that variation. The proposed research will contribute considerably to our knowledge of the history of West Germanic. In addition, a comparison of our findings with those of a similar ongoing project for the history of the Scandinavian languages undertaken by Platzack and his associates will be of interest to historical syntacticians. Finally, while the focus of our research concerns the course and nature of syntactic change, our results will help to clarify some unresolved problems in the synchronic grammatical analysis of West Germanic.