So I'm working on a novel set in an alternative 19th century. Not steampunk, but alternative. I want a world which is different to our own, but recognizable. The primary action of this story takes place in China, which recently fought and lost a war with the western powers over opening trade and has been rather firmly bought into the modern state system, despite the resistance of traditionalists and a growing banditry problem. It was suggested that I come here and ask for advice and help with building my world.
Here's what I've got so far.
Asia
China was reunited under the Song Dynasty after the last Song prince fled from his monastic prison to join the Red Turban Rebellion and became its leader. The man who in our history formed the Ming Dynasty instead became the Duke of Nanjing. Chinese history was mostly quiet after that as imperial authority was reestablished in the north and the local mongols beaten into the ground, though the Chengishids held out against the Oirats. The capital is Lin'An.
In 1870, a coalition of western powers provoked by Song intransigence landed an invasion force under the command of the British, delivered a defeat, and imposed terms that bought the Song into the modern state system.
Japan ???
Korea Tribute paying to Song Dynasty.
SE Asia Split between tributaries to the the British, French, Chinese and Siamese. The Siamese are very much the poor men here, but they retain full independence and control over much of their old empire by playing the foreigners off against eachother.
Europe
Hispania is a federation of the Spanish and Portuguese kingdoms, still under the 18th century constitution and now ruled by a local dynasty following the death of the last Habsburg ruler. Has a sizeable empire, but is perennially bankrupt. Enters into the story at a tangent, because it holds Macau under a Condominium with the Chinese.
France Ruled by Emperor Napoleon V in a semi-constitutional monarchy along the British model. Has a large, mostly empty empire, with serious influence in the Kingdom of Persia and Egypt.
Ireland Is independent under the House of Stuart, supported mostly by the catholic powers of France and Hispania. Split between a still primarily Anglo-Irish aristocracy and a pure, Gaelic peasantry. The British took temporary control again during the Napoleonic wars, but a reconciliationist government restored the House of Stuart to its Irish throne under Franco-British tutelage. Has no empire.
Great Britain
United under a branch of the German House of Hanover. British politics, without the Irish question dominating them in the 19th century, became somewhat more whiggish. Still built an empire, still rules the seas. Dominates India, Southern Africa and Australia, and shares Egypt with the French and Turks.
Ottoman Empire ???
Eastern Europe ???
Germany United as a federation following the Napoleonic Wars. Federation increasingly fell under the dominion of Prussia, became the German Empire.
Italy ???
Austro-Hungarian Empire ???
Russia ???
Greece Holds the entire Aegean coast following a massive Russian sponsored revolt during a complete collapse of the Ottoman state. Constantinople is its capitol. The Turks along the western coast of Anatolia are fleeing to the rump state of Turkey.
Scandinavia ???
North America
United States of America Very similar to our own in 1899. Perhaps slightly more expansionist. Well known for being parsimonious (cheap). Fought a brutal civil war. The free states won.
Mexico A Habsburg Monarchy, riven by civil war and
corruption.
South America
A constellation of Spanish territory, native tribal states, the Great Brazilian Empire (founded during the Napoleonic wars by claimants of the defunct Portuguese throne). The west coast may be under the domination of a semi-modern Inca State under Spanish tutelage. The south (Our timeline's Argentina and Chile) was never colonized successfully
Africa
Apart from the Great Amharic Kingdom (Ethiopia/Abyssinia), the Catholic State of the Kongo, and the Boer Volkstaat, the continent is nominally ruled by European empires.
Middle East
Divided between a tottering Anglo-French supported Ottoman Empire riven by succession wars, the loss of its European provinces, and the rising power of the Hashimids in the Arab provinces; a Persia dominated by French diplomats that extends almost to the borders of British India; and the Kingdom of Egypt and the Sudan, a British-French condominium nominally ruled by a local dynasty.
I'm looking for ideas to fill in the missing gaps on the map. I'm especially struggling with Japan and Korea, which will have a lot of relevance to the story just by being neighbors to China. One idea I had for Japan is Hideyoshi's regency won out against the Tokugawa, but then the issue I had is that would lead to aggression against Korea which may draw in the Chinese. And I don't know what a civilian-dominated Japanese medieval government would look like, though I can see it as hostile to the Chinese Empire.