When did Dunleary become Dún Laoghaire?

afaik most people in kells refer to it as kells and not as ceannanus mor. in fact don't know anyone who uses the irish name.

The only place I ever saw it was on Bus Eireann buses who always displayed Ceannanus Mor, never Kells! Although they do display both now on the buses.
 
Lookit, it's always a good one for confusing the tourists! Along with our local pronunciations of Dorset St and D'Olier St.
 
[SIZE=-1]Is it Bagnalstown or Muine Beag? What do the locals call it?[/SIZE]

Locals call it Bagtown or B-town. Or Bagenalstown. I've never heard any of the people I know from there call it Muine Bheag. And when you get the train down, it's always called Bagenalstown by the announcer.
 

I grew up there and am still a local when at home. It was always written as Dún Laoghaire or Dun Laoire (never saw Dunleary before this post). The locals still refer to it in english as Dun Laoire.
 
afaik most people in kells refer to it as kells and not as ceannanus mor. in fact don't know anyone who uses the irish name.

Nor do I.

But I have to admit that Kells, in common with most of the other examples (e.g. Kingstown, Queenstown, Maryborough) sounds very English - which could well be the main reason for the change to the Irish form (?)
 
And what about the Co. Cork town of Rath Luirc - also known as Charleville - and have seen postmarks 'An Rath.''
 
And what about the Co. Cork town of Rath Luirc - also known as Charleville - and have seen postmarks 'An Rath.''

Again, Charleville to me sounds very English - hence possibly the local preference for Irish form.