As nouns the difference between splendour and sublimity
is that splendour is standard spelling of from=British spelling|lang=en while sublimity is the state of being sublime.
splendour
English
Noun
(-)
Usage notes
The standard spelling in modern British English is splendour', with ' splendor being the American and dated British spelling.
sublimity
English
Noun
(uncountable) The state of being sublime.
(countable) Something sublime.