Here's a pilot video for a proposed animated movie about Botswana's King Khama III, who saves Botswana from being turned into a colony by touring Britain, winning the people to his cause, and finally confronting Queen Victoria at Windsor Castle.
(Sadly, this video has expired, but I am leaving this post online in case someone is looking for info on the project.)
Thank you to Mark Macauley for telling me about his screenplay and this video!
You can read about Khama III at Wikipedia, and you'll find books about royalty in Botswana on Royalty.nu.