IT IS hard to believe, but in just under two generations, what was arguably the largest and most successful empire ever (at least from the point of view of the rulers) simply vanished. What is even more remarkable is that much of it was only put together in the latter half of the 19th century.
In the 1850s, British Imperial Territories were composed of modern-day Canada (then known as Canada East, Canada West, Rupert's Land, the North West Territory and British Columbia), the United Kingdom (including all of Ireland), Australia, Tasmania and New Zealand, Burma, Ceylon and part, though by no means all, of India.
In Africa, the Empire was confined to the southern tip of the continent (the Cape Colony, British Kaffraria and Natal) and, in western Africa, to what were known as the Gold Coast Forts, and Sierra Leone and The Gambia.
In central and southern America there was British Honduras, British Guiana, the West Indies, Caribbean islands and the Falkland Islands.
And that was largely it. The Empire upon which the sun never set was otherwise a collection of islands in the Atlantic and Indian oceans, some cities in south-east Asia such as Singapore, Penang and Hong Kong, Sarawak (a small part of an island that is mainly Borneo), and, in the Mediterranean Malta and the Ionian Islands off western Greece.
Of these lesser outposts of Empire, two were of undoubted strategic significance: Gibraltar, occupation of which gave command of the entrance to the Mediterranean, and Aden, which guarded the entrance to the Red Sea.
Less than 100 years later - by the outbreak of the second World War - British global influence had mushroomed into what was truly an empire.
Everything held in the 1850s was retained (with the exception of the Irish Free State and the Ionian Islands) but added to it were vast tracts of Africa, the entire Indian sub-continent and large parts of south-east Asia.
The Empire now included South Africa and South West Africa (Namibia), Bechuanaland (Botswana), Northern and Southern Rhodesia (Zambia and Zimbabwe), Nyasaland (Malawi), Tanganyika (Tanzania), Kenya, Uganda, Sudan and British Somaliland.
The city of Aden had been expanded into the Aden Protectorate - a huge swathe across the southern end of the Arabian peninsula.
In central and western Africa, Nigeria had been acquired; the Gold Coast forts had become a full-blown country, as had Sierra Leone and The Gambia.
In the Middle East, Britain ruled Cyprus and Palestine and exerted very considerable influence in Egypt, Transjordan, Iraq, Kuwait, Bahrain and the Trucial States (modern Oman), each of which signed treaties of either friendship or protection with London. The 1850s holdings in India had by 1939 been consolidated to embrace all the states of modern India as well as modern Pakistan, Bangladesh and Nepal, and British influence effectively meant that London's writ also ran in Sikkim and Bhutan, two states in the Himalayas.
In south-east Asia, small possessions like Singapore and Penang were incorporated into a much larger holding - Malaya. The Sarawak foothold on Borneo had ballooned into most of the north and west of the island, including North Borneo and Brunei.
By 1939 the British had added Papua New Guinea to their portfolio, along with many Pacific islands, including Tonga, Fiji, the Ellice Islands, the Gilbert Islands, the Solomon Islands and the New Hebrides. Further across the Pacific, the Cook Islands had joined the Pitcairn Islands as part of the Empire.
In America, Canada had been consolidated into the single entity it is today but, apart from a small diminution of British Guiana in South America, there was no change. The US had, of course, been "lost" to the Empire in 1776.
And then suddenly, shortly after the end of the second World War, it all began to melt away. First India and Pakistan won independence and then the 1960s saw the great retreat from Africa - a retreat so rapid it was a mirror image reversal of the 19th century rush into the continent.
By the end of the 1970s, the British Empire had all but ceased to exist. At its height, several hundred million people were ruled, directly or indirectly, from London.
After midnight on Monday when Hong Kong is handed back to China, less than 200,000 people will be left in Britain's remaining colonial outposts.
