Oh, goodie! a simple inquiry about nomenclature has spawned a debate on Lancaster and York! yay!
Katisha, you should have wasted hours as a teenager playing “Kingmaker,” like I did. Then you would automatically know that on the Yorkist side, Edmund was third in succession after Richard of York and Edward of March (when playing the long version, of course).
With respect to the Lancastrian heirs, I think that the whole point of Henry VII’s claim was that there weren’t others left.
Henry IV had four sons: Henry V, Thomas, John and Humphrey.
Henry V died in 1422, leaving only one son, who became Henry VI. Henry VI in turn had only one son, Edward, Prince of Wales, who died in 1471. Henry VI died (likely murdered) shortly therafter.
Of the younger sons of Henry IV, Thomas died in 1421, John in 1445, and Humphrey in 1477. So all the clearly legitimate Lancastrians were dead by the time Edward IV died in 1483.
There were also the dubious Beauforts, sons of John of Gaunt, Henry IV’s father. Their claim to the throne was murkier because they were born illigitimate and subsequently legitimated. The first generation of Beauforts died out long before the Yorkists came to power: John in 1410, Henry in 1447, and Thomas in 1427. John had two sons: John, died 1444, and Edmund, who died in 1456. The second John’s daughter was Margaret Beaufort, who married Edmund Tudor, and was the mother of Henry VII. Margaret lived to a ripe old age, dying in 1509, the same year as Henry VII himself.
So, of all the Lancastrians, it looks like the only one alive in 1483, other than Henry himself, was his mother Margaret.
(Note: the above is based on Chambers Biographical Dictionaryand the genealogies in my Kitteridge Shakespeare. I hope it’s accurate, but would be pleased to hear if I missed someone.)