Work on the movement of phrasal categories has been a central element of syntactic theorizing since the earliest work on generative grammar. Work on the movement of lexical elements, heads, however, has been much less central until recent years. Chomsky's Empty Category Principle, requiring empty elements to be properly governed and requiring certain movement traces to act as proper governors, stimulated research on the properties of heads and how they behave with respect to movement operations. This in turn led to Travis' Head Movement Constraint and Baker's work on incorporation, and to Pollock's influential splitting of INFL (and thus the successive movement of finite verbs to their surface position). Parallel to these theoretical concerns, much attention has been focused on the description of verb-second languages and on the movement operations which place the verb in its 'second' position. This volume represents the latest work in an important field, from some of its leading researchers, and puts forward many ideas about relevant principles and parameters of Universal Grammar. It will have a significant impact on its field.