The British caubeen being of Highland Scots origin:

Who so ever began to introduce an Hibernian dress seems to have leaned heavily on Caledonian custom. The bonnet or caubeen does not seem to figure largely in Irish history and, indeed, a portrait (now lost) of Owen Roe O'Neill wearing what we would recognise as a caubeen circa 1610 is chiefly remarkable in that 'such a cap does not appear in any other Irish picture and may have been adopted from association with the Highland MacDonalds of Co Antrim.

http://www.royalirishrangers.co.uk/uniform.html

Mark - Ohio