UK: Platinum Jubilee: St Paul's Cathedral hosts service of thanksgiving for Queen Elizabeth II.

The video discusses the role of army reservists based in London, highlighting their training and service. It also covers naval traditions, particularly the use of white hats at sea to protect from the sun, and how these traditions were altered during the Queen's reign.

What is the location mentioned where the army is based?

How do reservists contribute to military service according to the text?