The oak tree is a symbol of England, representing strength and endurance. The term Royal Oak is used to denote the escape of King Charles II from the grasps of the parliamentarians after his father's execution; he hid in an oak tree to avoid detection before making it safely into exile.

Oak Apple Day or Royal Oak Day was a holiday celebrated in England on 29 May to commemorate the restoration of the English monarchy, in May 1660. In some parts of the country, the day was also known as Shick-Shack Day or Arbour Day.

"Heart of Oak" is the official march of the Royal Navy of the United Kingdom. It is also the official march of the Canadian Navy, as well as the Canadian Forces' Naval Operations Branch.
The music was composed by Dr William Boyce and the words were written by the 18th Century English actor David Garrick. Heart of Oak was originally written as an opera.

Decus et tutamen - красота, честь и защита

The tree we can see on the slide is not the original Royal Oak, which is recorded to have been destroyed during the seventeenth and eighteenth centuries by tourists who cut off branches and chunks as souvenirs. The present day tree is believed to be a two or three hundred-year old descendant of the original and is thus known as 'Son of Royal Oak'.

In 2000, Son of Royal Oak was badly injured during a violent storm and lost many branches. Another oak sapling was planted near the site of the original Royal Oak in 2001 by Prince Charles; it was grown from one of the Son's acorns and is thus a grandson of the Royal Oak.

In commemoration of the tree's significance in British history a number of places and things have been named after the Royal Oak. The Royal Oak is the third most common pub name in Britain.

The number of each is given in brackets.

http://en.wikipedia.org/wiki/Royal_Oak
http://en.wikipedia.org/wiki/England#National_symbols.2C_insignia_and_anthems
http://schools-wikipedia.org/wp/c/Charles_II_of_England.htm
http://www.contemplator.com/england/heartoak.html
http://www.youtube.com/watch?v=2mmbKR98dTw
http://www.youtube.com/watch?v=eQ75JZ3JP88