King John was so bad that, ever since, no King of England has been named John. Kings of England are usually named either Edward, George, William or Charles. Never under any circumstances will another king be named John.
It comes as a surprise therefore that genealogists tell us that King John is literally the father of us all. Almost the entire population of England is descended from King John, primarily through his illegitimate daughter Joan, the daughter of an unknown French mistress.
Joan had six children, who had more children. They were not considered royalty, as Joan was illegitimate, but they proliferated in great numbers.
It can easily be seen that, through Joan alone, all of England could become populated. Joan lived from 1188 to 1236. Since 813 years have passed after her birth, if one assumes that the population of her descendants doubled every 30 years, that means that 27 generations have passed since her birth. She would therefore have more than one hundred thirty-three million descendants, which is 2 to the 27th power.
This of course proves that all of us are bastards.
King John also had five children by his legal wife, and from these children are descended the entire Royal Family of England. Thus, it seems more than likely that every English person alive today is descended from King John.
(Who is Irish, English, Swedish and Scot)