My bewilderment about Edmund Somerset's locus standi in the matter of Glamorgan has been solved by reference to The End of the House of Lancaster by R.E. Storey - another book I am keen to recommend to anyone wanting to understand the complex background to the start of the so-called Wars of the Roses.
Anyway, in 1453 Somerset was was given charge of the lands of George Neville during his minority. This George Neville being the son of Elizabeth Beauchamp, half-sister of Anne Beauchamp on her mother's side - this particular Anne Beauchamp being Warwick the Kingmaker's wife. OK so far?
The only thing is that Richard Beauchamp, Earl of Warwick, his son Henry Beauchamp, Duke of Warwick, the guardians of Anne Beauchamp, Henry's little daughter, and finally the Kingmaker himself, in the right of his wife, the other Anne Beauchamp, had all of them held onto George Neville's share of Glamorgan. In the case of Richard Beauchamp, it was undoubtedly because his wife, Isabelle, mother of the aforementioned Henry, Elizabeth and Anne (Kingmaker's wife Anne that is) was the rightful owner of Glamorgan in preference to her own children.
But after Isabelle died (1439) it becomes more problematical, doesn't it? Presumably Henry Duke of Warwick got the whole pot because he was a male. Then his daughter got the whole of his inheritance. But when she died, surely the Despenser inheritance should have been divided between her aunt, Anne and her cousin George, heir of her other aunt? It's hard to discern a legal reason for George not getting his share at that point.
However in 1450 Warwick the Kingmaker was given a grant of all the lands formerly held by his wife's niece (Little Anne Beauchamp, as opposed to Big Anne Beauchamp, aka Mrs Warwick). This included the whole of Glamorgan. (Except for the Countess of Northumberland's dower lands, but that's another story.)
So when in 1453 Somerset was given the wardship of George Neville and started to press for possession of George's share of Glamorgan, we can understand why Warwick would be annoyed, even if, from an objective point of view, his case for possession seems a tad dubious.
There was 'military activity' in Glamorgan , and both Warwick and Somerset were ordered to appear before the King's Coucil to sort things out. Due to events, however, nothing substantive happened to settle the dispute, and Warwick continued in possession of all Glamorgan. He was, however, now second only to York in the I Hate Somerset Club.
The next post will try to summarise the remainder of Somerset's political career.