The total area of the United Kingdom is approximately 243,610 square kilometres.
The United Kingdom is a unitary state under a constitutional monarchy . Queen Elizabeth II is the head of the UK as well as of fifteen other independent Commonwealth countries
The kingdoms of England and Scotland, together with the kingdom of Ireland, had already been in a personal union as a result of the Union of the Crowns in 1603, when James VI, King of Scots inherited the Kingdoms of England and Ireland and moved his court from Edinburgh to London.
Various styles of music are popular in the UK, from the indigenous folk music of England , Northern Ireland, Scotland and Wales, to heavy metal . Notable composers of classical music from the United Kingdom and the countries that preceded it include William Byrd , Henry Purcell , Sir Edward Elgar , Gustav Holst , Sir Arthur Sullivan (most famous for working with librettist Sir W. S. Gilbert ), Ralph Vaughan Williams , and Benjamin Britten , pioneer of modern British opera .