] I have always thought of the Spanish island Majorca as just that, Majorca--I know of it from reading about the Georgian, Regency, Napoleonic eras.
] I just searched the web for info on Majorca and found it spelled Mallorca.
It isn't really a name change as such - more that the Balearic islands are asserting their own identity more these days.
As I understand it, Mallorca is more the local way of spelling it - Majorca is the English speaking way derived from Castillian Spanish. Presumably when the British were out there in force, they used the 'high' Spanish names.
In the same way, one of the other islands used to be called Minorca (well, by English speakers anyway) and is now called Menorca, although in all the time I've been there, the name has always been spelled with an 'e'.
The islands have their own language which is different again from Catalan. Last year in Menorca we noticed that many of the place names had changed subtly - for example Santo Tomas had become Sant Tomas. It's because the islanders want their cultural heritage to survive and they are changing place names, road signs etc. back to what they used to be. We were told that they (the names) had been changed under General Franco, but I don't know if that's true.
As I said, that's how I understand it but I may not be totally correct. If anyone knows better, I'd be interested because we are off there again this year. :-)