Cause and effect in Beowulf Book

For years I (mistakenly) taught my students that Beowulf was composed around the year 700 and written down about 300 years later. Kevin Kiernan, by his meticulous study of the actual Beowulf manuscript, has argued convincingly that the poem was in fact composed and written down at the same time, in about the year 1000; in fact, he believes the second Beowulf copyist (of two) was the anonymous poet himself. Much of this book is highly technical regarding his analysis of the manuscript -- but it's fascinating stuff and very readable nevertheless.