There is no way anyone can encompass and define the arts and culture of Britain using a single movement or time period. How could anyone, really, considering that Britain consists of very different cultures (established in England, Scotland, Wales and Northern Ireland)? In any case, Britain has managed to preserve much of the culture of its home states and territories on top of integrating new, influences as the world becomes more and more connected.
There is no official language in Britain, although 95% of its population speaks English pretty much exclusively. This has become the standard of communication in the country, although there have been movements geared to preserve the regional languages spoken in British territories such as Welsh, Cornish, Irish, Ulster Scots and Scottish Gaelic. The preservation and promotion of these languages have the added bonus of serving as a means of preserving actual cultures that are slowly being forgotten in the wake of the modern age. Parts of these cultures, of course, include old literature written and told in those languages.
This is indeed very important as much of early British literature is very rich. The earliest living literature of the territory was written in Celtic, after all, and the Ulster Cycle (which includes the famous Irish epic hero Cuchullain) is undeniably important to the development of British literature. Nevertheless, it seems that much of Britain's greatest contributions in the field of literature were written in English. This of course includes the oldest existing Anglo-Saxon epic Beowulf; as the Middle English dialect came into prominence, greats like Chaucer and the legendary Shakespeare rose in status as authors. They were quickly followed by the rise of novelists like Defoe and Fielding, before Burns' poetry revived poems. Poets like Wordsworth and Keats arguable became the greatest of their time, before the novel, too was revived by the likes of Dickens and the Bronte sisters. Today, Britain is seen by many as a literature capital – it has borne many respected writers of the modern and postmodern age such as George Orwell and T.S Elliot, and more contemporary greats like Terry Pratchett and J.K. Rowling.
Apart from literature, Britain had many contributions in other fields of art as well. It has one of the most distinguished theatrical traditions, the highlights of which included Morris dances, Christian morality plays, the long-living plays of William Shakespeare, and the thought-provoking productions of Irishmen George Bernard Shaw and Oscar Wilde. Andrew Lloyd Webber, who had written and composed musical hits such as the “Phantom of the Opera” and “Evita”, also brought much esteem to British theater.
Speaking of musicals, one cannot discount Britain's contributions to music as well. From the great Elgar to the talented John Tavener, it cannot be said that Britain is lacking in musical talent. In fact, a good chunk of rock and roll had been influenced by British bands like the Rolling Stones, the Beatles, Pink Floyd, Queen, Elton John, David Bowie, and, more recently, Radiohead and Coldplay. Other types of music such as acid house and trip hop were also originated in Britain. As it is, Britain is home to a rather large number of concert halls and orchestras.
Performance arts aside, there is much to be admired about British visual arts and architecture. Although Britain did not historically distinguish itself in visual arts and architecture, the stonework and structures associated with the area have nevertheless always been proven as notable among aficionados. But Britain was one of the first to embrace a degree of modernism in these; pop art was born in England some time in the 1950's, and the Arts and Crafts architectural style were inspired by British thinkers.
There are so many other cultural contributions that Britain has shared with the world; and it seems to be planning to keep contributing well into the far future.