A bit tangential, but 'Leicester' is one of those wonderful British place-names that doesn't really follow any English pronunciation rules and you just have to know the right one...
In this case 'Leicester' is pronounced 'Lester'.
In this case 'Leicester' is pronounced 'Lester'.
Latin gives us, via Old English, the "-cester" in all of the placenames mentioned elsethread, as well as "-chester" and "-caster". Old English gives us all of the "ton"s, "hamp"s, and whatnot. The "win-" in "Winchester" is Celtic, as are the "dor-" in "Dorchester" and the "man-" in "Manchester". The "lei-" in "Leicester" means an unploughed meadow, a.k.a. a lay or lea.
* https://en.wiktionary.org/wiki/lay#Etymology_6
When one isn't a native Latin or Old English or Celtic speaker and cannot even understand placenames in England, it does seem a little silly, and missing a huge elephant in the room, to be worrying about Welsh placenames. (-:
This is why the names don't follow Modern English pronunciation rules. They aren't actually Modern English.
cester -> ster (or 'stɜː' round my end)
Mornington Crescent!
(No pronunciation trickery on that last one, it is just the name of an absurdist parlor game)
I was here for almost 20 years before I learnt that Heighham is pronounced as just "Ham".