I just noticed something else:
[ . . . ] and ealle his eorlas and ealne his þeodscype [ . . . ]
translated:
[ . . . ] and all his earls and all his people [ . . . ]
Assuming that the noun "people" was considered to be singular in "number" back then, as it is today (in American English), it appears from this passage that there was declension of the adjective "all", based on number.
I've studied a teeny tiny bit of the history of English, and in doing so I've considered it odd that in some ways the language became LESS complicated, not more complicated, over the past one thousand years or so, in particular when compared with certain aspects of other Germanic languages.
In modern American English, we can see that the pronunciation of the definite article varies depending on the noun that immediately follows it (roughly pronounced "thee" or "thuh", as in "thee apple" and "thuh man"), but the proper spelling is "t-h-e", regardless of the pronunciation -- but there is no inflection by case, gender, number, tense, person, mood, or voice.
By contrast, from what little German I know, the definite article in modern German can be "der", "dem", "den", "die", or "das" (inflection by case, by gender, and by number).
"My greatest fear is that the audience will beat me to the punch line." -- David Mamet