Oak Apple Day
Falling on 29 May and known as ‘Oak Apple Day’, this is a former public holiday which, although less celebrated today as a calendar custom, symbolized an event of crucial importance in English history, the traditions of which, in parts of England are still very much kept alive. To understand it we have to look back to the year 1660 to see quite how it came to bear this name and why the symbol of the oak was such a particular one. However, the year 1630 is also important to help us understand the true meaning of Oak Apple Day, because it was on 29 May of this year, that ..... read the rest of this article at http://royalcentral.co.uk
There is a song and related tune associated with Oak Apple Day - entitled The 29th of May
Also:
https://www.learnenglish.de/culture/oakappleday.html
http://projectbritain.com/calendar/May/oakday.html
https://www.countrylife.co.uk/out-and-about/theatre-film-music/bring-back-oak-apple-day-72535