When I saw this film for the first time back when it was released, I was vastly disappointed. I wanted better dialogue, better costumes, and above all more fidelity to actual history. Some of the big plot engines, especially the one involving Michael York's and Prunella Ransome's characters, never happened in reality, and I have this stickler historical mentality that feels if you make a historical movie about real people, it should be, you know, accurate.
I was a critic at the time, and as I recall, I gave it a fairly scathing review. But upon subsequent catch-as-catch-can late-night viewings (and why why WHY isn't this out on video and DVD?), I have come to temper my opinion. Michael York especially is outstanding---when he's onscreen you can't take your eyes off him, though I very much doubt the real-life Guthrum the Dane looked anywhere near so cute---and I so wish that Clive Donner and the writers had given his rather swoonalicious Guthrum---the Beatle Viking!---a whole lot more to do.
(It's not in the movie, but in historical fact Alfred and Guthrum made a peace treaty afterwards that split England between them, Alf taking the south and west and Guthrum taking the north and east. So really Alfred bargained for his peace, and if it's Alfred the Great, it should darn well be Guthrum the Great as well...)
David Hemmings's performance is as good as can be expected, given some of the thankless dialogue, and he is both tortured and twinkly; while Prunella Ransome's Queen Aelhswith is not only decorative but intriguingly liberated for a noble ninth-century lady (however historically inaccurate and ultimately unconvincing).
And the supporting cast is nothing short of tremendous: Ian McKellen (and you can see Gandalf the Grey in his eyes...), Colin Blakely, Vivian Merchant (who reportedly insisted on playing her character as a mute after a dialogue rewrite was not forthcoming), Julian Glover, Peter Vaughan, Sinead Cusack in her film debut.
Pity the script didn't give any of them but McKellen anything to really get into, though Vaughan munches a bit of scenery. If they'd had something better to work with, "Alfred the Great" might have been the Anglo-Saxon "Lawrence of Arabia"...
