Beowulf is preserved in a single manuscript written out around the year 1000, but there are many reasons to believe that the poem was composed several centuries before this particular act of manual reproduction. Most significantly, the meter of Beowulf reveals that the poet regularly observed distinctions of etymological length that became phonologically indistinct before 725 in Mercia. This dissertation gauges the explanatory power of the hypothesis that Beowulf was composed about three centuries before the production of the extant manuscript. The following studies test the hypothesis of archaic composition by determining whether it is able to accommodate independent forms of evidence drawn from the fields of linguistics, textual criticism, and literary history.