At its peak, the British Empire was the largest formal empire that the world had ever known. As such, its power and influence stretched all over the globe; shaping it in all manner of ways.
World War One appeared to add yet more colonies to the British Empire in the form of mandates. It was estimated at this time to cover between a quarter and a third of the globe and that it represented an area of over one hundred and fifty times the size of Great Britain itself.
World War II would see much imperial territory threatened or temporarily lost. Despite being on the winning side, the Empire would not recover from the geo-political shifts caused by this Second World War and would enter into a period of terminal decline. India was the first and largest area to be shed, then the Middle East and then Africa. Various Caribbean and Pacific possessions held on a little longer, but most of these also went their separate way. The last of the major colonies to be lost was that of Hong Kong in 1997.
Historians have long debated how and why the British were able to amass such a formidable and expansive empire in the years since 1497. And why were the British able to supplant the Portuguese, Dutch and Spanish Empires in the 17th and 18th centuries and effectively see off French, Russian and German challenges over the 19th and early 20th centuries? These debates still rage and there is no definitive answer but there are some commonly stated reasons.
This was a popular combination of factors given for the rise of the British Empire in the late 19th and early 20th centuries. The Protestant aspect of Christianity was seen by many within the British Empire as part of the larger battle with the more Catholic nations of Continental Europe. Ever since the Reformation, religion represented not merely a spiritual difference between the Catholic and Protestant churches, but was part of a far larger cultural and political competition between deadly rivals. Portugal, Spain and France were the Catholic nations who developed successful commercial empires before the English and Dutch were able to do so. Religion gave an excuse for this commercial rivalry to turn into military and political competition. The very success of the Protestant nations in challenging the Catholic hegemony in the New World and the East Indies seemed to confirm that God might be on the Protestants side after all - although this did ignore the fact that the English and Dutch coreligionists were just as frequently found at the throats of one another.
It was certainly helpful that the Protestant work ethic meant that Christian and commercial ideals could be reconciled fairly easily and in fact was thought to manifest itself in the improvement and development of British civilization in general. In pre-industrial Britain, the combination of the these three factors would lead to the creation of the settler colonies in North America. Devout Christians would look for economic freedom from feudal relationships in this New World. However, mercantilism and then the industrial revolution could mean that the commercial aspect could take on a more sinister role as monopoly power, slavery or exploitative working conditions became a temptation hard for investors or capitalists to resist. It was reassuring to many such capitalists that they could hide behind the idea that by investing in enterprises and schemes around the world with a reasonably clear conscience and with the idea that they might also be serving a modernizing and civilizing goal.
The civilization aspiration could be damaging in its own right. It assumed that British civilization was innately superior to those it was subjugating. Indeed, the very subjugation process confirmed the superiority of British civilization! It then assumed that the new rulers were obliged to improve the subjugated peoples that it had taken under its wing with large doses of Christianity and commerce. Of course, this appealed to the positive aspirations that many Imperialists held for the future of a benign Empire. It offered a justification for Imperialism. However, it could also justify some of the more extreme Social Darwinist ideas of racial superiority and it allowed for treating the subject peoples as innately inferior.
In summary, Christianity, commerce and civilization were a neat way to justify the uniqueness of the British Empire and yet give it a justification for continuing into the future. It could also be deeply patronizing and justified cultural imperialism and racial stereotyping, and yet there was a surprisingly large strain of truth behind this reason for the British strain of imperialism
Slavery would show just how exploitative and morally bankrupt this system could descent to. Plantations needed labor and labor was available, relatively cheaply, in West Africa. It was when slaves started revolting and rising up in rebellions that questions were asked back in Britain; why precisely was the government spending money and resources supporting slave owners against slaves? They had not shared the profits in the "good" years, why should British taxpayers support them now that they were suffering? Surely it was there own problem.
The British had no monopoly on technological innovation. Gunpowder, the printing press and navigational equipment were all developed and improved on the continent or further afield yet. Europe from the 15th century onwards was becoming a dynamic place where new ideas were swirling around with unnatural haste. Britain was benefiting from this much wider European Renaissance and Age of Enlightenment. Yet it was also in a position to take these ideas, and many others, much further as it would become the first nation to harness the power of steam, which in turn would unleash an Industrial Revolution and an avalanche of high quality, mas/produced goods that would flood the markets around the world. They, in turn, would provide a technology gap that non-European nations would find it difficult to compete with. Precision made muskets, rifles, machine guns, train locomotives, steam ships would provide the relatively small and outstretched British armed forces with unparalleled advantages. They could take on vastly larger enemies and yet beat them off, subdue and suppress them. British weaponry was very effective and its communication systems allowed it to shepherd its meager resources to devastating effect. Even its medical resources would improve enough to allow its soldiers and sailors to penetrate deeper and more inaccessible areas. Britain was not the only nation to enjoy a technological advantage over non-European nations, but its combination of industrial might and maritime power meant that it had a peculiar advantage, one that would not be challenged until the development of guerrilla warfare and tactics in the 20th century.
This situation would not really be transformed until the 18th century. The Glorious Revolution of 1688, where Dutch King William of Orange took control of the English Crown, would reduce, but not remove, Anglo-Dutch rivalry. It was not until the Seven Years War, from 1756 to 1763, that the Royal Navy would be able to take on the far richer and more powerful Kingdom of France. Ironically, this was also due to the Glorious Revolution, in that the Dutch brought sophisticated banking techniques, including the formation of the Bank of England. That allowed the British to borrow money to build a huge Navy with the idea of paying back the loans once Britain had been victorious. The French Navy had no such infusion of investment, and so were hard pressed to see off the challenge from the Royal Navy, especially on the global scale of what was really the first "World War" in that it stretched over the globe. In some ways, the French were able to get some revenge by helping the American Revolutionaries in the 1770''s and 1780''s in their humiliation of the British. But this in itself would be a false dawn for the French Monarchy. They had invested huge quantities of money to challenge the Royal Navy and help the Americans to win the Revolutionary War, but without the benefit of receiving tangible assets to recoup this investment. It is not an understatement to say that one of the prime reasons for France''s own Revolution was because their own cupboard was bare after helping the American Revolutionaries.
"The Destruction of ''L''Orient'' at the Battle of the Nile" by George Arnald
Communism was an easy ideology to sell to poor, exploited and oppressed peoples around the World, Communist organizations and groups therefore became a major resister and opponent to Imperial regimes the World over, especially when they became tied to Cold War politics. Unfortunately, when agricultural or primary resource colonies gained their freedoms with the promises of a Communist Utopia to fulfill it did not take long for disappointment, cronyism and corruption to undermine and discredit Communism as a viable form of government. It may have given some people inspiration to remove their imperial overlords, it just could not deliver on its promises.
Of course, there is rarely a single answer to the complicated realities of politics, economics and military rivalry. There is probably no single reason to explain how Britain created such a vast institution. Various isolated reasons, advantages and localized situations would combine to create a series of justifications for seizing isolated colonies that combined to form the huge and expansive British Empire.