Word order in Old English has some properties in common with those in other Germanic languages, such as V2 in a main clause and Vf-final order in a subordinate clause. However, it had idiosyncratic traits that led to word order changes in the later stages of English. Focusing on the word order of three-verb clusters (modal+have/be+participle) in Old English, this paper argues that the rise of functional projections with the head in its initial position shaped changes in word order in the history of English.