| cast |
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| Series Regulars | |||
| |||
| Bradley James | Bradley James as Arthur | Katie McGrath | Katie McGrath as Morgana |
| Colin Morgan | Colin Morgan as Merlin | Angel Coulby | Angel Coulby as Gwen |
| Anthony Head | Anthony Head as Uther | Richard Wilson | Richard Wilson as Gaius |
| John Hurt | John Hurt as The Dragon | | |
| |||
| Recurring & Guests | |||
| |||
| Santiago Cabrera | Santiago Cabrera as Sir Lancelot | Michelle Ryan | Michelle Ryan as Nimueh |