A country now part of Europe. An island repeatedly invaded and settled. The Anglo-Saxons (Angles, Saxons and Jutes) had the most lasting effect in the south and the Vikings in the north. The Romans left their roads but took with them their knowledge of central heating.
Well known for various things. Beer, sense of humour and their hatred of any nearby neighbour which has made them historic enemies. Particularly down on the French and Scots, this has fuelled a tremendous amount of folk material through the huge number of battles they've had. When the English weren't having battles, various bits of the monarchy were usually marrying into the opponents families leading to more folk songs. The English also absorbed a lot of customs this way.
Of course there were other influences such as the Normans, but they hardly count.