Deleted Scene: The original cut of the film was over three hours long. Among the many scenes that were lost - but was briefly glimpsed in the trailer - was a scene where Lancelot rescued Guenevere from a forest bandit.
Director John Boorman originally wanted to do a film adaptation of J.R.R. Tolkien's The Lord of the Rings trilogy, compressing the trilogy into one very long film, but he couldn't get the rights to it so he made Excalibur instead. Reportedly his screen treatments sexed up Tolkien's story quite a bit, including but not limited to giving Frodo Baggins pointless nude scenes he didn't have in the books and having the House of Healing scene between Eowyn and Aragorn feel like a sex scene (as he planned to cut out Arwen and have Eowyn settle down with Aragorn, which reportedly was Tolkien's original idea). Generally the Arthurian myth sounds like it was better suited to him than Tollkien!