The dating of Beowulf has attracted considerable scholarly attention and opinion differs as to whether it was first written in the 8th century or whether the composition of the poem was nearly contemporary with its eleventh century manuscript and whether a proto-version of the poem (possibly a version of the Bear's Son Tale) was orally transmitted before being transcribed in its present form. Albert Lord felt strongly that the manuscript represents the transcription of a performance, though likely taken at more than one sitting. J. R. R. Tolkien believed that the poem retains too genuine a memory of Anglo-Saxon paganism to have been composed more than a few generations after the completion of the Christianisation of England around AD 700, and Tolkien's conviction that the poem dates to the 8th century has been defended by Tom Shippey, Leonard Neidorf, Rafael J. Pascual, and R.D. Fulk, among others. An analysis of several Old English poems by a team including Neidorf suggests that Beowulf is the work of a single author.
The claim to an early 11th-century date depends in part on scholars who argue that, rather than the transcription of a tale from the oral tradition by an earlier literate monk, Beowulf reflects an original interpretation of an earlier version of the story by the manuscript's two scribes. On the other hand, some scholars argue that linguistic, palaeographical, metrical, and onomastic considerations align to support a date of composition in the first half of the eighth century; in particular, the poem's apparent observation of etymological vowel-length distinctions in unstressed syllables (described by Kaluza's law) has been thought to demonstrate a date of composition prior to the earlier ninth century. However, scholars disagree about whether the metrical phenomena described by Kaluza's Law prove an early date of composition or are evidence of a longer prehistory of the Beowulf meter; B.R. Hutcheson, for instance, does not believe Kaluza's Law can be used to date the poem, while claiming that "the weight of all the evidence Fulk presents in his book[b] tells strongly in favour of an eighth-century date."