alt Hacker NewsArticle could benefit from some editing: the poem is from variously the 7th, 8th and 9th centuries! After reading a few times I get that one date is the supposed composition date, the second is the publication date of Beade, and the last is the date of transcription for the copy in Rome.
Yeah, that threw me as well.
Also worth pointing out that the Old English version at each of those dates probably varied quite a bit. This was the time period over which Old English was being influenced by external factors such as Norse and Latin.