There were no African nobles in the court of Elizabeth I of England in the 16th century. Having black actors play some of the parts in this movie makes as much sense as having women as generals in that era. If you are going to do a historical film, either stick to the facts of the time period or don't do the film. Maybe the next time they can have a Leonard Nimoy look alike with Spock ears play the English ambassador to Scotland.
Review of Mary Queen of Scots
