In this monumental contribution to Old English philology, Geoffrey Russom integrates important discoveries about syntax, meter, and oral-formulaic composition to interpret striking differences between Old English poetry and prose, including many differences that have previously evaded detection. The prehistory of English word order is traced from about 300 BCE, when alliterative meter was born, to the era of Beowulf (about 700 CE). Evolution of poetic word order is then explained as a response to syntactic evolution -- a response significantly delayed by formulaic poets who valued their ancient technique. An analysis is provided for every clause in Beowulf, with each concrete example accompanied by verse numbers for all similar examples. Russom's integrated approach brings to light general principles of verse structure and formulaic composition that apply in other languages and other poetic traditions as well.