So this was a thing I did, an alternate history 1859 map where among several changes in the history:
1. The Fourth Crusade never happens, with the Byzantine Empire managing to consolidate power in the Western Aegean and the Balkans. In managing to regain control of this region, the Ottomans do not advance any further West than Anatolia, instead focusing their efforts in the Middle East and Africa. With the Eastern Roman Empire re-ascendant, Sicily is later reconquered and brought back into the fold of the Empire. Constantinople never falls, and the Byzantines remain bulwarks of Orthodox faith for another several hundred years, becoming the longest contiguous empire in human history (when including the whole Roman empire): 2,712 Years.
2. England wins the 100 Years War, which ends the Capetian dynasty's reign over their French homelands. This drastically changes the power dynamic of Europe entirely. The Holy Roman Empire is weakened by the combined strength of the new Angevin Empire. Within another 150 years, English is no longer spoken, but a mixture of Middle English and French, known as Anglois. Ireland and Scotland are conquered later, and when colonization begins,
Great Angleland (The union of England and France, and later the Netherlands, Scotland, and Ireland), as its called, ends up as the strongest colonial power in the world (much like the real-life Great Britain). All of the French territory is colonized much like in real life, but as a combined effort. This leads to North America being primarily Anglois. However, the United States of America never exists; without an independent France to support them, their pleads for international aid fall on deaf ears, and the rebellious 13 Colonies are defeated and destroyed. With no USA, Mexico, which still gets independence from Spain, controls all of the Rio Grande, Rocky Mountains, and California. Additionally, Spain retains control of Florida, becoming the base of Spain's colonial operations.
4. The Wars of the Roses don't happen, and as a consequence, the English Civil Wars are changed. In fact, the English Civil Wars aren't over Charles I's misdeeds and authoritarian nature. Since the Plantagenet dynasty never died out and killed each other (the Yorks and Lancasters), it's rather a later Plantagenet in the 17th Century that would cause the
First Anglois Civil War. The authoritarian nature of King Louis XIII causes Ireland to attempt to attain independence from Angleland, and while dealing with that rebellion, he imprisons many nobles who refused to lend him money for the war effort. This would cause friction with Parliament; in 1632, King Louis dissolves the Anglois Parliament entirely, which causes the military to turn against him. Things do play out similar to how it would in the original timeline, with Louis being imprisoned and put on trial by the Anglois Parliament, and later beheaded. However, the biggest difference is that the French lords remain steadfastly loyal to the crown. Despite the mass-carnage, the Plantagenet dynasty wins out, with Louis XIII's son, William III, becomes King.
3. The religious teachings of Jan Hus are largely successful, and in by the early 15th Century,
the German states turn away from the Catholic Church and create the Deutsche Hussitenkirche (German Hussite Church), which creates a massive theological crisis in Europe. The next series of wars throughout the next 300 years (1450s-1780s) would be waged to settle the debate between Catholic and Hussite supremacy. The Holy Roman Empire would be ripped apart, and in its wake, two powers would stand tall: the Austro-Hungarian Empire, and the Kingdom of Prussia. Austro-Hungary maintained their ties with the Catholic Church, with Prussia acting as the bulwark of the Hussite faith. As a result, Denmark and the Scandinavian Empire would also adopt the Hussite faith.
5. Poland-Lithuania is never conquered. Seems like a deceptively simple decision, but keep in mind that at one time, Poland-Lithuania was a incredibly large nation with tons of culture and a pretty good military to boot. The reason Poland was conquered was because of foreign influence from the general Sejm (parliament) of Poland, which had broad veto powers. Instead, the constitution of Poland is rewritten in the early-18th Century, and with it, they are better prepared to counteract the threats placed on them by Austria, Prussia, and the Russian Empire. By the 1830s, Poland is firmly entrenched in the Hussite faith, and with it, becomes a strong ally of Prussia. Prussia and Poland's alliance serves to spook Russia into staying within their sphere of influence.
6. The French Revolution never happens. Napoleon never happens, the Wars of the Coalitions don't happen, and the Congress of Vienna doesn't happen... well, not quite in the way it does originally. What instead happens is that authoritarianism and monarchies continue to last for much longer than they did in the original timeline. However, with England already having a parliament, many nations begin to adopt this system internationally, to much success. However, there is a major European war that does break out in the 1800s, with regards to abolition. The
20-Years' War breaks out over a diplomatic incident between Great Angleland and Spain, which leads to all nations of Europe making alliances. Of course, Angleland ends up on the winning side, which causes many of Spain's colonies to break off (most prominently Mexico). Portugal also suffers from this war with Brazil declaring independence. Through settled negotiation, abolition is an international issue, and is largely successful in the coming decades.
7. Gran Colombia succeeds. Speaking of Spain's colonies breaking away... Simon Bolivar successfully leads Gran Colombia as a permanent institution within South America. Not much to say about this, it just seemed to make sense to me.