In the bedroom scene after Elizabeth's coronation, her ribs and flat stomach are visible, even though she's supposed to be heavily pregnant.
The portrait of Margaret of Anjou viewed by Elizabeth and her mother is actually a copy of a historic portrait of Elizabeth herself.
Henry Tudor had no legal claim to the crown. Though a descendant of John of Gaunt, his family line was illegitimate and was legitimized on the condition that they were barred from the throne.
The portrait of "Margaret of Anjou viewed" by Elizabeth and her mother (and then burned at the direction of the Earl of Warwick) is actually a copy of a portrait of Elizabeth Woodville herself.
Old Dutch text can been seen engraved on the stone on which Lady Margaret Beaufort is lying in the church, revealing that the show is being filmed in Belgium.
Elizabeth's pregnancy bump comes and goes, appearing in the opening and vanishing during the coronation and subsequent nude scenes and reappearing shortly before Elizabeth gives birth.