What is an oak apple?

An oak apple is also known as an oak gall. It is caused by the larvae of a cynipid wasp.

What is oak apple day?

Monarchists celebrate Charle's II's birthday and his escape from the Roundheads on 29th May. It is called 'Oak Apple Day' in memory of the time when the king hid in an oak tree following the Battle of Worcester. Thanks to the protection of this tree 'the Boscobel Oak' in the grounds of Boscobel Hall, Staffordshire, Charles was eventually crowned king of Great Britain and Ireland on 29th May 1660; and his supporters celebrated in a manner that would surely have been condemned by the Puritans of Oliver Cromwell's Commonwealth.

Cromwell (1599-1658), the leader of the Parliamentary side in the English Civil War, raised a highly successful cavalry force (known as Ironsides) and declared Britain a republic in 1649. He was also part of a special commission that tried King Charles I and condemned him to death that same year. Nevertheless, the king's son (also Charles), having spent nine years wandering through Europe after his near escape, issued a Declaration that promised a general amnesty and freedom of conscience. Parliament accepted and he was proclaimed king.

The wearing of a sprig of oak on the anniversary of Charles' crowning showed that a person was loyal to the restored king. Those who refused to wear an oak-sprig were often set upon, and children would challenge others to show their sprig or have their bottoms pinched. Consequently, this day became known as Pinch-Bum-Day. In parts of England where oak-apples are known as shick-shacks, the day is also known as Shick-Shack Day. It is also likely that the royal association conceals a pagan tradition of tree worship.

These days it is traditional for monarchists to decorate the house with oak branches or wear a sprig of oak on 29th May. In All Saints Church in Northampton, a garland of oak-apples is laid at Charles II's statue. Whereas, in Grovely Forest, Salisbury, a procession takes place at first light, accompanied by the sound of horns. It is also traditional to drink beer and eat plum pudding - especially at the Royal Hospital in Chelsea, which was founded by Charles II on this very day.

On or near this date, a curious figure called the Garland King rides through the streets of Castleton, Derbyshire, at the head of a procession. His head and the upper part of his body are completely hidden by a 'garland' - a heavy wooden construction, shaped like a beehive and covered with flowers and greenery. On top of the garland is a small posy of flowers, which is called the 'queen'. Behind the king rides his queen (at one time played by a man in woman's clothes), accompanied by a band and children dressed in white. After pausing to dance at various points along the way, the procession arrives at the church and the garland is pulled up to the top of the church tower and fixed to a pinnacle. The 'queen' posy is then placed on the town war memorial.

http://www.learnenglish.de/Temp/May/OakAppleDayUK.htm