Meter
The Anglo-Saxons wrote what we call alliterative poetry after its most salient feature, the system of alliteration that binds its verses together and is largely responsible for its distinctive sound. Similar metrical systems are found in Old Icelandic, Old Saxon and Old High German: all of these cultures inherited a common Germanic meter, which they adapted as their languages and cultures changed. English poets continued to write alliterative poetry as late as the fifteenth century, and the meter has often been revived—most notably by the twentieth-century poet Ezra Pound.
There is more to Old English meter than alliteration. The poetry also employed a strict rhythmic scheme, which you will find to be markedly different from the rhythms employed by later poets such as Chaucer and Shakespeare. These later rhythms are based on the regularly timed recurrence of stressed syllables in the line. In Old English meter, the line consists of two verses (also called half-lines) divided by a syntactical boundary called a caesura. Each verse must conform to one of five rhythmic patterns (ortypes, as they are generally called), which we designate with the letters A-E. Verses of all types have in common that they always (well, almost always) contain two stressed syllables, called lifts, and two or more groups of unstressed syllables, called drops. The arrangement of lifts and drops depends on the type. The lifts do not necessarily come at regular intervals.
Why some rhythmic patterns were permissible in Old English poetry while others were forbidden is a subject of vigorous debate among scholars. The answer, if we had it, might tell us why the permissible rhythms sounded “good,” or sounded “like poetry.” At present the most plausible theory is that the rhythms of poetry were based on those of ordinary speech, but with added rules that enabled listeners to recognize the boundaries between verses and lines. In much the same way, we can recognize the organization of Shakespearean blank verse when we hear actors recite it, even though there are no rhymes to tell us where the lines end.
Modern editions of Old English poetry print it as you have seen it in this book, in long lines with the caesura marked by a space. You should be aware, though, that in Old English manuscripts the poetry is not broken into lines, but rather written continuously, like prose. Like other editorial conventions (such as the use of modern capitalization and punctuation), the arrangement of poetic lines in printed editions is a compromise: it makes Old English texts more accessible to modern readers, but it conceals some interesting characteristics of Old English manuscript culture. You should track down a facsimile of the manuscript of a poem you are reading