OK. I have to go out soon and won't have internet access until tonight - so I will replace this with a quickie question which you will know is right when you get it !
The answer to the previous question is that they all have names which date them as being originally Saxon settlements. Ford, Ham, Worth, Bourne,Ton etc. are all Saxon place names. Portsmouth and Manchester were both Roman towns - and Grimsby was a Danish/viking settlement. By at the end of a town name (Pronounced Bu in Danish) is often also found in present Denmark, Sonderby, Brondby etc.
The next question : There is only one football league club in England which has none of the letters found in 'mackerel' in its name - which is it ? When you get it then set the next question.