Edward did not father Queen Isabella's children.
An old canard which occasionally crops up on badly-researched websites and in sensationalist, badly-researched novels, based entirely on the assumptions that a) Edward II was gay and therefore incapable of intercourse with women, and b) Isabella began a relationship with Roger Mortimer in late 1325 and therefore may well have committed adultery with him or another man a few years earlier. (The eldest of Edward and Isabella's four children, Edward III, was born in November 1312.) The first-ever suggestion that I've been able to find that Edward III was not Edward II's biological son comes from Paul Doherty's novel Death Of A King, published in 1982 - 670 years after the birth of Edward III.
In fact, it is physically impossible for Roger Mortimer to have fathered Edward III, as he was in Ireland at the time of the boy's conception. He was also in Ireland in 1315 and 1317 when Edward and Isabella conceived their next two children, and away from court when their youngest was conceived in 1320. [Ian Mortimer, The Greatest Traitor: The Life of Sir Roger Mortimer (2003), pp. 49-50, 69-70, 87, 100-01.]
A comparison of Edward and Isabella's itineraries proves conclusively that they were together approximately nine months before the births of all their offspring, and they were together in York in February/March 1312 to conceive Edward III. Easter Sunday fell on 26 March in 1312, so Edward and Isabella must have conceived their son during Lent, when intercourse was forbidden. This hardly lends credence to the notion that Edward slept with his wife unwillingly; Lent gave him the perfect excuse not to have sex with Isabella, if he didn’t want to. In November 1315, they were together at the royal hunting lodge at Clipstone in Nottinghamshire to conceive their second son John, born August 1316. In September 1317, they were together in York to conceive their daughter Eleanor, born June 1318. In October 1320, they were together at Westminster to conceive their daughter Joan, born July 1321.
No record of the fourteenth century gives even the slightest hint that anyone believed Isabella had taken a lover and that Edward was not his son’s real father. Privacy is a modern invention, and Isabella probably had less of it than anyone else in the country; she spent every minute of every day surrounded by ladies-in-waiting, damsels, chamber and wardrobe staff, and many other servants, and it is impossible that she could have conducted an affair and kept it secret. The purity of royal and noble women was considered of vital importance, and it is unlikely that they ever had much, if any, chance to be alone with a man who wasn’t a close relative. People who believe that Isabella took a lover in early 1312 who fathered her son - and bear in mind that the queen was only sixteen years old then - must explain how she managed this seemingly impossible feat without anyone ever noticing. Her relationship with Roger Mortimer began in late 1325 and occurred when she was in France and beyond Edward’s influence, after their marriage had irrevocably broken down and long after she had borne Edward’s four children. This cannot be taken to mean that Mortimer, or anyone else, had been her lover years before.
It was only in the late twentieth century that speculations about Edward III’s paternity arose, on the basis that Edward was gay and therefore incapable of sex with women, which says far more about modern notions of sexuality than it does about fourteenth-century realities. Edward II had an illegitimate son called Adam, so obviously he wasn't repelled by intercourse with women, and might have enjoyed it enormously for all we know. Whatever Edward’s contemporaries might have thought of his sexuality, no-one doubted that he fathered Isabella’s children - let me repeat that there is not the slightest hint in any medieval source to suggest that anyone thought he didn't - and therefore there is no reason for us to doubt it.
For the kind of utter rubbish we're dealing with here, see this page, which speculates that Edward I was the real father of Edward III - yes, that's the Edward I who died on 7 July 1307, five years and four months before the birth of his grandson. Even people who study medieval English history repeat this kind of speculative nonsense as though it's valid.
Paul Doherty's novel Death Of A King, and Charles Randolph Bruce and Carolyn Hale Bruce's novel Bannok Burn, make Roger Mortimer Edward III's father, which, as pointed out above, is impossible. Doherty goes as far as placing Edward III's date of birth in March 1312, eight months earlier than it really happened, in an attempt to make this theory more plausible, but it is still impossible, as Mortimer was also in Ireland in the summer of 1311. Edith Felber's 2006 novel Queen of Shadows has Isabella abandoned in Scotland in 1312 and having an affair with some mysterious Scotsman who is never named, who (apparently) fathers Edward III. Utter tosh; the closest Isabella ever got to Scotland in 1312 was Tynemouth, seventy miles from the border.
No historian worth his or her salt would ever write that Edward II did not father Isabella's children, so if you see this claim anywhere, be aware that the writer hasn't a clue what s/he is going on about.
Posted by Kathryn Warner October 2009