No-one has responded to my question on the earlier thread, so, if I may, I'll repeat it. Are the Houses of Lancaster and York currently regarded as Plantagenets? As I said earlier, Antonia Fraser has the last Plantagenet King as Richard II.
No, Richard II. He was deposed by his cousin, Henry IV, son of John of Gaunt, founder of the Lancastrian dynasty according to Antonia FRaser; Edward IV was the first Yorkist king.