This one's a sequel to The White Queen and The White Princess, based on a series of novels by Philippa Gregory covering the women of the royal dynasties of York (late Plantagenet) and Tudor. Gregory's no Sharon Kay Penman or even Elizabeth Chadwick (a bit lighter on historical accuracy and heavier on bodice-ripping), but I'm watching because it's a historical period of interest for me.
First of all, as with the first two miniseries we have to go with the theory that Perkin Warbeck really was Richard of York, the youngest of the Princes in the Tower, Elizabeth of York knew it, and she condoned not only his execution but that of their pitifully tragic cousin Edward of Warwick, who spent the majority of his life imprisoned simply because he was a male too genetically close to the throne. Most historians agree it's highly unlikely that the younger of the skeletons found in the White Tower wasn't Richard, although it's quite possible that Warbeck could have been an illegitimate son of Edward IV considering his womanizing reputation. Up to the audience to decide how endangered Elizabeth's sons actually were or if some of the motivation was that Elizabeth liked being Queen and didn't want a downgrade to princess again - or to see her husband, who she has come to love, dead like her uncle Richard III instead of her brother.
As the Spanish Princess begins, Ferdinand and Isabella's daughter Catherine starts off in a bad position as she arrives to marry crown prince Arthur.. A PTSD suffering Elizabeth hates her from the get-go, simply because of the heavy price she paid in her family's blood to make the marriage happen - Isabella wouldn't let her daughter eventually share a possibly contested throne, of course. Also haunting the shadows is Edward of Warwick's sister Margaret, who alternates between not being able to keep her mouth shut about what happened and in deathly fear of her sons ending up like her brother and cousin.
A game-changer occurs when Arthur dies young, and Catherine sets her sights on his brother Henry - eventually to be Henry VIII of six wives fame - in desperation to keep the British alliance for her family. In a "downstairs" plot, the stakes are perhaps just as high for her head lady-in-waiting, whose lover - a kindhearted Muslim - will face a gruesome fate if the alliance doesn't hold, with Spain now under the Inquisition...
A bit of a fun watch, although take the accuracy with a huge grain of salt.