For a change, an alternative history post. :-)
I read (or rather re-read) an interesting story in John Carmi Parsons' Eleanor of Castile (1995, p. 33) the other day. When Edward I and Eleanor of Castile were staying at Caergwrle Castle, also sometimes called Hope Castle, in August 1283, a fire broke out in their bedchamber one night, and they barely escaped with their lives. The fire gutted the castle, and it was never rebuilt.
I checked Edward I's itinerary, and he and Eleanor were at Caergwrle Castle on 26 and 27 August 1283. My first thought was, that was eight months before the birth of Edward of Caernarfon on 25 April 1284, so Queen Eleanor must have been some weeks pregnant with him at the time. It was fascinating to me to contemplate that Edward II might never have come into existence, if his parents had succumbed to the fire!
This led me further in my thinking: what would have happened if Edward I and Eleanor had indeed died in that fire? The king's heir in August 1283 was his and Eleanor's only surviving son Alfonso, who was born in November 1273, so was nine years and nine months old at the time. Alfonso would have succeeded to the throne at that point, and yes, that means that England would have had a child king called Alfonso. Heh. But, Alfonso died suddenly on 19 August 1284, still only ten years old, so would only have reigned for just under a year (I'm presuming here that whatever killed him would still kill him in this alternative scenario). If we assume for a moment that Queen Eleanor survived the fire which in this scenario killed her husband, and assume she wasn't too physically hurt or traumatised and didn't miscarry, she would have given birth to Edward of Caernarfon eight months later (though not necessarily in Caernarfon). The boy would have succeeded to the English throne on the death of his brother Alfonso, before he was four months old, meaning a very long reign and a long minority.
Assuming now that Queen Eleanor did also die in the fire, on the death of our King Alfonso in August 1284 the male line of Edward I would have expired, as Edward of Caernarfon would have been wiped from existence. Edward I's two younger sons Thomas of Brotherton and Edmund of Woodstock, born in 1300 and 1301 from his second marriage to Marguerite of France, would never have been born either. Edward I had five surviving daughters, however, who in August 1284 were fifteen, twelve, nine, five and two.
In real life, shortly before his second daughter Joan of Acre married the earl of Gloucester, on 17 April 1290, Edward I faced the possibility of the extinction of his male line, and declared that in the event of the death of himself, his son Edward of Caernarfon, and any other male heirs of his body or heirs of his son's body, his eldest daughter Eleanor should be queen in her own right. If Eleanor died without heirs, Edward I's next daughter Joan would be queen, and so on. Edward I evidently preferred the idea of his throne passing to his female children than to his male Lancaster relatives.
Eleanor was born in June 1269, so was fifteen in August 1284, when I'm imagining that 'King Alfonso' died a year after their father. Would her rights have been considered as heir to her younger brother Alfonso? I think it's more likely that Edward I's younger brother Edmund of Lancaster (born in January 1245) would have been preferred, a man in his late thirties, to a girl in her teens. The usual concerns about a female ruler would have arisen, that she wouldn't be able to defend her country militarily, that England would be ruled by her husband, a foreign king or prince (Eleanor was betrothed for many years to Alfonso III of Aragon). So England would, most probably, have had a King Edmund, succeeded on his death in June 1296 by his eldest son King Thomas (b. c. 1278), and the Lancastrian dynasty would have been on the throne over a century before they really were (Henry IV in 1399). Thomas of Lancaster, in real history, married Alice de Lacy, daughter and heir of the earl of Lincoln, in 1294. As the son of the king, however, he might well have made another match, with the daughter of a European king or duke or count, and had legitimate children, which in real life with Alice, he didn't. If not, he would have been succeeded as king by his brother Henry (born c. 1281).
In real life, Edward I's daughter Eleanor married Count Henri III of Bar in September 1293 (her long-term fiancé Alfonso III of Aragon having died suddenly in 1291), and had two children born in about 1294/96, Edouard I, count of Bar, and Joan, countess of Surrey. Eleanor died in August 1298, and her son Edouard, then aged about three, became next heir to the English throne behind Edward of Caernarfon until the birth of Edward I's son Thomas of Brotherton in June 1300 (who was heir to the throne from the death of his father on 7 July 1307 until the birth of his nephew Edward III on 13 November 1312). If Eleanor had been the eldest surviving child of her father in 1284, and rightful queen of England, presumably she would have made a different marriage. Who would this have been, and would he have been willing to fight for Eleanor's rights against her uncle Edmund of Lancaster? Might there have been a civil war in England between the daughters of Edward I, their husbands and their descendants, and the Lancasters?
A world without Edward II and Edward III, and their many descendants. No Hundred Years War, no Wars of the Roses. Our history would be unimaginably different. Thank goodness Edward I and Queen Eleanor escaped the fire in August 1283!