Beowulf

Beowulf is known as one of the greatest works of literature in Old English. It is an epic poem that has approximately 3,200 lines describing the adventures of the hero Beowulf. The poem is divided into three parts: Beowulf's fight against Grendel, the revenge of Grendel's mother and Beowulf's last battle against the dragon.
Beowulf is known from one single manuscript that is housed by the British library. The was a part of the Nowell Codex which originated from the late 10th century or early 11th century. Sir Robert Cotton later bound the Nowell Codex with the Southwick Codex and called it Cotton MS Vitellius A XV. Unfortunately, a fire in 1731 damaged the manuscript, charring its edges and making it very fragile. Further conservation efforts have kept the codex from deteriorating further, though the strips used to secure the parchment covered the text.
 Nevertheless, the language used in Beowulf is beautiful, filled with alliteration, imagery and symbolism. Reading the poem, you can see how life was before, when people died young and few could read. And if you listen closely, you might hear "the harp's rejoicing call and the poet's clear songs, sung of the ancient beginnings us all"(Beowulf v. 4-6) in Hrothgar's hall.

The original manuscript is available in digitized form here.

If you're interested in reading more, this post by the British Library's Medieval Manuscripts blog is about the contents of the Beowulf manuscript, and this one is about some interesting aspects of the Beowulf manuscript.