Basic sum-up of Centuries of Shadow on the verge of the 20th century.
The POD is relatively small, with the Somersett Case of 1770 taking a different route. Slavery was banned in Britain and Ireland itself but a form of neo-serfdom was permissable. Over the decades, unfree labour has expanded in importance, adapting to the demands of the Industrial Revolution. Debt bondage, the concept of selling oneself into the security of serfdom, the wealth and prestige that was possible if you gained villein status, turned the mass of working poor into an owned resource that would make Marxists cry out in pain. The Enlightenment was throttled in its cradle, would-be republican abolitionists squashed in North America in the 1820s, the French Revolution settled by compromise that ultimately allowed the King to reclaim much of his power from the parlements, and aristocrats retain much of the power around the world.
The most powerful of the world's empires is the British Empire, known officially as the Empire of the Britons. Britain makes no pretence that its empire exists for a civilising purpose, loudly espousing the superiority of the white man (ironically somewhat broader a category than OTL's Empire). The Empire is dominated by corporate interests, the most powerful of which is the Royal Africa Company and the British Pacific Company. The integration of Overseas Corporate Provinces has added the voices of MPs in the pocket of the colonial corporations to Parliament, and as the Empire has grown, they have come to dominate discussions and have established an imperial consensus. Smaller corporations are the Hudson's Bay and Arctic Company, and the East India Company. Slavery in various forms is ubiquitous across the Empire, and parts of British Africa are positively empty, being opened up to white and Arab settlement. There is a strict Imperial caste system which favours the aristocracy, a mercantile elite, and the military. Caste mixing is severely discouraged. Sexually and religiously, Britain is far more permissive and throughout the Augustine Age, Britain has developed a reputation for decadence and hedonism. The influx of Arabs into British society has caused growth of Islam across the Empire, and female suffrage has been allowed. Strict property qualifications are still enforced however. The Empire has erected strong trade walls around herself and the landowning aristocracy has hence grown enormously wealthy and powerful. The monarchy retains a position of power it had long since shed in our world, and under Emperor Ernest Augustus II, various members of the Royal Family sit in the House of Lords. The Empire has long taken an aloof, detached view of Europe but recent events may draw her into the mounting tensions.
The British Empire is a leading member of the Imperial Alliance, which includes the Empire of All the Russias and the Portuguese Empire. The Russians adapted their current system of servitude to industrialism in a similar fashion to the British, and have radicalised from simple feudalism to a more centralised Orthodox theocracy. They are uncomfortable with Britain's social liberalism and some of the habits they have picked up from their African subjects but the two empire have few if any territorial disagreements and agree that the Europeans are weak and soft, that the right sort of people should rule, and that freedom is an over-rated concept. The Tsars kept going south in this world, and without Britain to halt them in Afghanistan, they have annexed Persia. From there, the Russians have purchased islands in the Indian Ocean and agreed a protectorate over Ethiopia. Russia is more liberal than the British when it comes to race, and her class system is more fluid. But in terms of religion they are extremely ferocious and have enthusiastically persecuted Muslims and Buddhists throughout their empire and sphere of influence. The other member of the Imperials, Portugal is the least extreme of the three. They maintain a strong slave trade which brings profits to Britain as well, and the Portuguese African colonies are also becoming home to white colonists wanting to strike it rich outside the motherland. Portugal is a more traditional absolute monarchy, in stark contrast to the corporate aristocracy of Britain and the theocracy of Russia. Serfdom is rare in Portugal's empire, as the numbers of slaves are so great, its hardly worth bothering. Lusitanic Catholicism is aggressively encouraged and thrust upon the Empire's inhabitants, but not nearly to the same extent as in Russia. The excommunication of Portugal when the Papacy fled to Spain after the Germanic Wars allowed Portugal to take their own path which has lead to Lusitanic Catholicism closely mirroring Vodou in many respects. The dead and death are venerated to an extent that somewhat worries the life-loving Britons.
Europe has for the last century enjoyed peace and prosperity under the auspices of the Congress of Europe. Tensions exist but wars are waged outside Europe, in the colonies. France is the strongest member of the Congress, and is Britain's greatest enemy. Her colonisation of Africa was mostly motivated by the pursuit and destruction of slavery, and the containment of the Royal Africa Company and its Shartry Legions. Other members of the Congress include the Empire of the Spanish, the Kingdom of Italians, and the Empire of Hungary-Austria. One of the main things which keeps the Congress united is fear and hatred of the Imperials, and fear and hatred of the German nation. The Germanic Wars convinced all of Europe that Germany should not be allowed to exist as a nation, and the Congress meets regularly to ensure that unification does not come about. The decline of the Ottomans in Europe (as opposed to Asia where they are doing well) has however distracted them, and growing calls for German reunification are being foolishly dismissed as the wails of a minority. Spain has a loose confederal empire and suffered at the hands of Britain and France earlier in the century. But the Empire has seen a resurgence and is now one of the world's truly Great Powers.
Beyond Europe, other powers exist. India gears up for war as the Moghuls turn from their pursuits in Central Asia and look once more to India to reclaim the lost glory of Araungzeb, inevitably seeking conflict with the loose and vaguely democratic Marathan Confederacy. Japan seeks to imitate the Europeans and has ambitions of ruling as hegemon over all of Asia. China is divided between a foreign influenced, progressive coastal region and a xenophobic, traditionalist interior, and the showdown between the two could decide who emerges from the 20th century the premier power of the world.
War is coming to Europe, and soon to the world. As the Ottomans withdraw from Europe the Congress scrabble over the pieces, and squabble amongst themselves. Germany is re-emerging as an nationality, and the power of nationalist movements is ignored in Paris and Madrid. The Imperial Alliance is increasingly concerned with the activities of extremely anti German Hungarians, and as the map of the world is filled in, smaller powers are eagerly looking for their 'place in the sun'...