What if Elizabeth of York, daughter of Edward IV and Elizabeth Woodville, born in 1466 was born a boy? I assume he would be called Edward and would be 17 by the time his father dies in 1483 so he's be old enough to rule, hopefully avoiding the regency and later the usurpation of Richard III. How will Clarence and Warwick's rebellion play out if Edward has a 3/4 year old son? Likely there will also be no Tudor dynasty and the York dynasty will probably last a lot longer.