Great Britain. Geographical Position Britain comprises Great Britain (England, Wales, Scotland) and Northen Ireland. G.B. is situated on the British Isles, which lie to the north-west of mainland Europe. The British Isles is the geographical term for a group of about 5,000 islands covering the area of about 242,000 sq. km. The largest island is Britain of G.B., which is also the largest island in Europe. The next largest island is Ireland which is made up of Northen Ireland (of Ulster) and the Irish Republic (also known as Eire), the latter being politically independent of the British Government. The North Sea, the English Channel and the Straight of Dover which is as narrow as 21 miles separate G.B. from the European continent. It is washed on the Western coast by the Atlantic ocean and by the Irish sea.