Characters like å and ø are considered distinct letters but they originated as diacritics. Diacritics are small symbols which can be added to existing text to r

Characters like å and ø are considered distinct letters but they originated as diacritics. Diacritics are small symbols which can be added to existing text to remove ambiguities and aid in pronounciation. So the scripts started with the latin alphabet and then added various squiggles to the existing letters.