Bright's Anglo-Saxon Reader/Anglo-Saxon Versification
Anglo-Saxon poetry is composed in a kind of blank-verse, in long unrimed (but alliterative) and ungrouped (i.e. stichic) lines.
A. General Principles 
1. Every line consists of two parts, the first half-line and second half-line; these half-lines are separated by a cæsura and united by alliteration (i.e. initial rime; end-rime occurs occasionally, but merely as an incidental ornament).
2. Every half-line has two rhythmic stresses, or accents, and consequently two rhythmic measures, or "feet"; it is a structural unit and has a scansion of its own, independent of that of its complementary half-line. In contrast to the second half-line, the first half-line is more favorable to the expanded and heavier forms of the foot.
3. The "foot" (or measure( in its simplest form consists of two parts, an accented and an unaccented part (arsis and these). However, two additional forms are employed: a foot of one part only (an arsis), which is employed in combination with a foot of three parts, of which one is an arsis (having the chief rhythmic stress), another has a secondary stress, and the third is unaccented, being the true thesis.
4. The arsis (or rhythmic stress) requires a long syllable (the vowel must be long in quantity, or, if short, the sullable must be closed with a consonant) or the equivalent of a long syllable. This equivalent is called a resolved stress and consists of two syllables, of which the first (with one of the word-accents) is short is quantity and the second is light enough in accent to combine with the first to produce with it the metric equivalent of a long syllable. But there are special conditions under which the arsis consists of a short syllable.
5. The thesis (or unstressed part of the foot) consists of a varying number of syllables, which are either unaccented or subordinate in emphasis. No metric distinction is made between long a short syllables in the thesis.
6. Alliteration (initial rime, consisting in the agreement of the initial sounds of words or syllables) is employed to unite the two half-lines into the larger rhythmic unit of the complete line. Alliteration is restricted to syllables in the arsis (and marks the most emphatic of these); any additional alliteration that may occur in teh thesis is to be regarded as accidental and therefore without significance in the structure of the line. The alliterating syllables have the same initial consonant (but the initial combinations st, sp, and sc are exceptional in alliterating only each with itself, not with any other initial s), or they have an initial vowel sound, any vowel or diophthong alliterating either with itself or (more commonly) with any other vowel sound.
The alliterating syllables are distributed as follows: (a) In the second half-line it is only the first arsis that shares in the alliteration. (b) In the first half-line both the first and the second arsis may alliterate; or the first only; or (less frequently) the second only.
7. The rhythmic stress, or the ictus, which distinguishes the arsis, coincides in general with the emphasis required by the sense. The four stresses of a complete line are therefore on the four most significant words or sullables of the line. These are not restricted to syllables with the primary word-accent, but may include syllables with a secondary word-accent, such as the radical syllable of the second member of a compound noun or adjective and the more important formative and derivative syllables (see Outline of Grammar, ch. 5, note).
The words that are made prominent by the rhythmic stress (of which some are made still more emphatic by the alliteration), being logically or rhetorically the most significant words in the line, are chosen according to the gradation of sentence-accent. Thus, nouns, adjectives, infinitives, and participles, intrinsically significant in a sentence, are employed only with rhythmic stress (primary or secondary) and are excluded from the true thesis. Next in this order may be placed the adverbs, which are, as a class, accented in the sentence and are, therefore, usually in the arsis. As to the verb, in its finite forms, it has normally a weak accent in the principal clause, but is more or less strongly accented in the subordinate clause. This distinction is to some extent reflected in the gradations of the rhythmic stress. Although the verb of the principal clause is not excluded from an emphatic arsis (with alliteration), it is very frequently placed in an arsis of weaker stress (such as the last arsis of the line); and it is often relegated to the thesis. The remaining grammatical categories are subject to the usual exigencies of sentence-accent, rhythm, or emphasis. An ictus on a personal or demonstrative pronoun, or on a preposition, for example, must be warranted by special conditions.
B. Rhythmic Types 
The structure of the half-line, the primary structural unit in Anglo-Saxon versification, is represented in the following five types:
1. Type A. /_ x | /_ x 
In type A the rhythm, in its simplest form, is trochaic:
|stīðum wordum, Gen. 2848a,||/_ x | /_ x|
|heorðgenēatas, M. 204a,||/_ x | /_ x|
|wundorlīce, Ph. 359b,||/_ x | /_ x|
The second (or final) thesis (as also in type C) never exceeds one syllable. However, the first thesis (as in B and C) admits a varying