Historians increasingly believe that the stories of the hero king of British legend and his chivalrous knights have their roots in France
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However the legend had an effect on King Edward III who had a round table for Knights at Windsor Castle:-
Some think that there is a link to Knights of the Garter.
Spain's Valencia Cathedral houses a relic that may be the Holy Chalice used by Jesus at the Last Supper – it has the right size, material, and history.