For the purpose of this post I am going to assume that everyone’s father was as given in standard family trees. The question of whether the eldest 14th Century Beaufort was actually a Swynford both legally and biologically, and the issues around the fathering of Katherine of Valois’ children I leave to others to untangle. Such matters merely complicate the case.
In 1396/97 the four Beaufort children of John of Gaunt were comprehensively legitimised by both Papal Dispensation and an Act of Parliament. Without going into tedious detail, this rendered them legitimate in both Canon and Common Law terms, as though their parents had not only been free to marry in open church before their birth but had actually done so. They were under no legal disabilities whatsoever.
Of course, at that time, there was little question of their having a claim to the throne as there was a host of people with a more senior place in the queue. A few years later, once their half-brother Henry IV had ascended the throne, they moved up several places. Henry, whose own claim was far from unanimously accepted, went to the trouble of passing two Succession Statutes. By the second he entailed the crown on his children and their heirs, both male and female. He made no mention at all of anyone beyond that, and this was not unreasonable. He had six children in all, and I suspect you would have got very long odds on a bet that only one (the future Henry V) would produce a legitimate heir, and a single legitimate heir at that.
John Beaufort, Earl of Somerset, asked his half-brother for an Exemplification of the Beaufort parliamentary legitimacy Statute. Henry obliged by issuing Letters Patent confirming the Statute, but specifically excluding the Beauforts from the succession. Henry’s motives for making this exclusion are not known, and it is probably better to say no more than that. Were I to speculate, I might suggest some fairly outlandish theories – even perhaps illogical ones. However, as already indicated, he probably assumed that the matter would never arise anyway.
Some people have questioned whether Henry had the right to effectively amend an Act of Parliament. Under present law he certainly had not, but then again under present succession laws he would not have been the sovereign in the first place. The King’s authority in such a matter was much less clear in the 15th Century than it is today. Indeed it remained a matter of argument right through to the Bill of Rights of 1689. So it is simplistic to say that Henry was not entitled to add the condition. He clearly thought he he had the right, as he could easily have presented Parliament with a Bill on the subject had he considered it necessary.
Here the matter rested until the reign of Henry VI, when the matter of the succession became a political issue again. With the King’s uncles dead, the potential candidates were York, Somerset and Exeter. Something may be said for each of them.
York was descended from Lionel of Clarence in the female line, which made him senior to anyone else – including, unfortunately, the King. So this line of descent was tacitly ignored for the time being. In the male line he descended from Edmund of Langley, Gaunt’s younger brother.
Somerset, being a Beaufort, could claim he was heir male to Henry VI, prior to the birth of Edward of Lancaster. All that was in his way was Henry IV’s exclusion clause, and indeed York’s claim from Lionel of Clarence, which was not overly stressed.
Exeter was descended from Gaunt’s daughter Elizabeth, and as such was undoubtedly possessed of a strong claim to inherit the Duchy of Lancaster after Henry VI. The Beauforts certainly had no right to it, as they did not descend from Blanche of Lancaster. Given the Henry IV exclusion clause, Exeter could claim to be heir-general to the King – provided of course you ignored York’s pesky claim from Lionel of Clarence.
The Wars of the Roses dealt with all these claimants one way or another. But after the Battle of Tewkesbury and the death of Henry VI in 1471, matters were greatly simplified. Edward IV was both heir general (through Lionel of Clarence) and heir male (through Edmund of Langley) of Edward III, and his hereditary claim was unimpeachable.
The surviving Beaufort was Margaret, Lady Richmond. Had she been a man, she might have been able to claim to be heir male of Edward III, although Henry IV’s exclusion would still have got in the way. As it was, she could only possibly claim to be heir general if all the legitimate descendants of Richard, Duke of York, male and female, ceased to exist. It really is as stark as that.
The alleged illegitimacy of Edward IV’s children and the bar of attainder against Clarence’s son only went a small way towards removing this queue of heirs. Moreover, it should be remembered that there were other Lancastrian claimants, the heirs of Gaunt’s daughters, Philippa and Elizabeth of Lancaster, who arguably had as good a claim as, if not better than, the one Margaret Richmond possessed.
It is small wonder then that admirers of Henry VII often state that he ruled by right of conquest, since he had no hereditary right whatsoever. What is odd is that they seem to think such a claim acceptable. It was not at the time, as lawyers were well aware of the disastrous effects of a claim by conquest on the rights of landowners. The truth is his thin claim was legitimated by Act of Parliament, an Act which did not touch on his antecedents at all, but made his rule as legal as was possible and ensured that property owners (save those who had fought for their lawful King at Bosworth) did not suffer from Henry’s accession.