Sidney Poitier just about carries his role off, as a Moorish prince obsessed with a mythical great golden bell ("The Mother of All Voices") - reputedly made by monks many years ago. The rest of the cast, however, are fish out of water - Richard Widmark and Russ Tamblyn are not at all plausible as Viking raiders/explorers and the ebbs and flows of the storyline and the pretty verbose dialogue stretch the imagination well beyond the point when it stops being fun and starts being dull. Oskar Homolka gets up to some mischief as the only potentially realistic Viking "Krok" but then Lionel Jeffries and Gordon Jackson show up and it is laughable again. The film does have a good, lavish, look about it and the attention to detail (costumes etc.) are suitably sumptuous but it is way too long and wastes a good adventure story.
