Rise and Fall of the Yugoslav Empire
Alternate Result at the Battle of Kosovo
In the real timeline, the Ottoman Empire had won the Battle of Kosovo in 1389. In this timeline called Timeline Heliopolis, the Serbs had won the Battle of Kosovo instead of the Ottomans.
After the Turkish counterattack aimed at the Serb heavy armor that was charging at the Turkish wing command, the Serbian forces regrouped at the upper hill that overlooked the battlefield, and harassed the incoming Ottoman army. Repeated Serb counter attacks had led to the Ottoman forces retreating from Kosovo all the way into northern Greece.
With the Serb victory at Kosovo, they were now in a better position to counter the Hungarian invasion that was looming over the border. Eventually, the Kingdom of Hungary saw the strength that the Serbs had demonstrated over the Ottoman armies.
With the Serbs having won the Battle of Kosovo and the decision of the Hungarian Kingdom not to invade from the north, The Serbian Empire flourished for the past century. However, the exploration of the New World hasn't escape its attention, which led to the explorations of present day North America and much of South East Asia. Before the exploration, the Serbian Empire united with the Kingdom of Montenegro, acquiring access to the sea. The Serbian Empire also included all of Macedonia and Greece, both territories that were formerly under Ottoman rule.
The first acquisition of Serbia's first colony occurred after its role in the alternate Spanish-Serbian War in 1764, after the Seven Years War. The Kingdom of Spain, wrecked by its defeat in the Seven Years War after the British occupied Cuba and the Philippines, faced another threat. This time, the Serbs had challenged Spanish superiority at the naval Battle of the Mediterranean, which Spain narrowly won. Although Serb naval power was weak at that time, it eventually grew thanks to British support, who at first supported Serbian ambitions after its contributions in the Seven Years War. Serbia's colony however, was the Gibraltar colony which would eventually be under British control. However, Britain's naval superiority was threatened by the expansion of more Serbian fleets anchored in the port of Bar in the Adriatic.
Year 1768 was the worst year for Serbia, which went to war with Britain over control of the Balkans. Britain's objective in the Anglo-Serbian war was the free access to Africa via the Balkans. The conflict also drew in the Hungarian Kingdom, which occupied Croatia.
Britain's first victory in the Balkans was at the Battle of Podgorica, when the British army overran Serb positions stationed in the city. The war also drew in the Russian Empire, anxious to get its revenge for its loss in the Seven Years War. Russian forces had invaded the Hungarian Kingdom, and defeated the Hungarian army at the outskirts of Budapest. British gains were rapid, occupying Nis, as well as other cities and towns. However, Britain's first defeat of the war was at the Battle of Belgrade. The battle in the Serbian capital was bloody and brutal, plus frequent harassment form native resistance groups operating in the city. Eventually, Belgrade was overrun by British forces.
For the first time in almost three centuries, Serbia was occupied by a foreign power. The Anglo-Serbian War ended in a British triumph, which occupied Serbia, as well as Croatia and Bosnia from the Hungarian Kingdom. Russia once again lost the war to its possible rival, having been denied the chance for access to a warm water port. Now, Britain has control of the Balkans, as well as South East Asia and North America, having defeated Spain, France and Serbia in a conflict that gave a rise to the British Empire.
The opportunity for revenge occurred when the colonists in the Thirteen Colonies rebelled against Britain in 1775. Serbia took advantage of this opportunity to resume its resistance against British occupation by assassinating a British Deputy Assistant to the military governor at the time.
Struggling for independence was the vocal point of the British-occupied territories and colonies' goal of driving its imperial masters out of its own territory. During the American Revolution, particularly in the late stages of the conflict, Serbia and Croatia sent volunteers to fight the British, until they were defeated in 1783. During that time, Serbia and Croatia were respectively liberated by the incoming Russian army, who entered the revolution on the side of its South Slav brothers.
Serbia pretty much stayed out of the conflict in the early stages of the Napoleonic Wars. However, with the French Empire starting to encroach Croatian territory, Serbia almost went to war with France. It wasn't until the French invasion of Spain that Serbia started to invade Spanish held Philippines. With Spain busy fighting off French occupation, Serbia quickly drove off the Spanish at the Battle of Vigan.
Nearly at the end stages of the Napoleonic Wars, Serbia turned against France in its opportunity to rekindle relations with Britain and Austria, who were both smarting from the loss of the control of the Balkans.
With Serbia's acquisition of the Philippines in 1815, the Serbs then proceeded to control Indochina, which consists of present day Vietnam, Laos and Cambodia. However, Serbia got into a war with the Netherlands over the Dutch East Indies in the Serbo-Dutch War of 1825. The aftermath of the victory in which Serbia earned gave rise of the South Slavic empire in South East Asia.
Serbia consolidated its control of its colonies further by expanding its economic development, particularly in the islands of Sumatra and Java in present-day Indonesia, and Manila in the Philippines.
With Croatia free from foreign control, it too started to seek colonies for its growing stable economy. However, Croatian ambitions clashed with Serbian ambitions, which came close to war. Luckily, both nations were too weary from the wars that they had to wage in order to survive.
American Civil War
When the American Civil War erupted, Serbia and Croatia first stayed neutral in the early stages. The reason for that was because both nations were threatened by Britain and France to stay out of the conflict, or face consequences.
However, the threat didn't keep Serbia from contributing its forces to primarily Union forces. Croatia didn't contribute any forces at all, instead it kept alert for any possible future conflict with Britain. But the aftermath of the American Civil War ended with a Confederate victory, and Britain was poised to invade Serbia once again, only this time at its colonies.
Second Anglo-Serbian War
The attack on Manila harbor was known to Serbian authorities, who were planning this conflict after the disastrous event during the American Civil War. In 1866, Britain invaded the Philippines once again. The first invasion was almost a hundred years ago. This time, Serbia went fully prepared for the combat. The war would have gone longer had not the Russian Empire intervened on its South Slavic partner's side.
When the war was over, Britain was forced to pay reparations to Serbia and Russia in goods as a result of its defeat in the Anglo-Serbian War. The timely intervention of Russia at the Battle of the Mekong River had proved to the British that it needed a partner quickly.
New Empires Emerge
In 1867, during the Anglo-Serbian War, the Austrian Empire had managed to unite with the Kingdom of Hungary, creating the Austro-Hungarain Empire. Germany had emerged in 1870 as a result of unification. Its first victory in combat resulted in the Franco-Prussian War, in which France lost. Italy also emerged back in 1866, and were planning an alliance with Germany and Austria-Hungary.
German fears of a powerful Serbia was already realized when it witnessed its industrial power in its South East Asian colonies during the peak of its economic boom in 1887. Austria-Hungary also feared Serbian domination of the Balkans when Croatia refused to accept a proposal for a three way monarchy between Austria, Croatia and Hungary. Croatia at this time had annexed Bosnia, and Serbia campaigned to capture the region of Vojvodina.
Japan also became a merging power back in 1877, after the US helped modernize its army. Serbia, wanting to also modernize its army, also asked the US for help. As a result, a US-Serbia treaty had came into effect. Russia also was aware of what was happening in the Balkans, and signed a treaty with Serbia.
Serbia and Croatia planned to be neutral in any case a future conflict broke out, but with Britain planning on joining the Triple Alliance as well as CSA, they may not have much choice. The Second American Civil War broke out in 1890, with the CSA winning it once again. The Russo-Japanese War of 1904-1905 was contested over the control of Korea and Manchuria, in which Japan won. However, Japan also lost its first modern war during the Serbo-Japanese War as a sign of retaliation for Serbia's support for Russia in the Russo-Japanese War. The Serbo-Japanese War was fought over Serbia's South East Asian colonies, in which the victor had kept control.
The planned alliance between Britain, Germany, Austria-Hungary, the Ottoman Empire, and Japan couldn't be realized because Britain was more concerned about France and the Confederate States being potential enemies if it joined with Germany. The United States also couldn't join Germany's side, for fear of losing support of its Slavic allies. So, a three way alliance was formed with Britain, France and the Confederate States being the Triple Entente, Germany, Austria-Hungary,and Turkey being the Triple Alliance, and the United States, Russia, Japan, Serbia and Croatia being the Big Five Powers. During the 1900's, former Ottoman Empire territories had already broken away with support of Serbia and Russia. As a result, Romania and Bulgaria became independent and joined the Big Five Powers as minor members. Italy later joined the Big Five Powers as a belligerent in 1910.
World War One Heliopolis Timeline
Serbia had covertly planned the assassination of Franz Ferdinand in Sarajevo while on a state visit to Croatia. Like in the real time line, Austria-Hungary blamed Serbia for the assassination, and sent an ultimatum. When Serbia refused to accept the ultimatum, Austria-Hungary declared war on Serbia. The Russian Empire then mobilized its troops and declared war on the Austro-Hungarian Empire. Germany did the same thing and declared war on Russia. Japan also mobilized and declared war on Germany, Austria-Hungary, and the Ottoman Empire. At first, Britain and France would sit this conflict out, but the desire to get revenge on the United States, Serbia, Russia and Germany proved too much to handle, and declared war on the Big Five Powers as well as the Triple Alliance (Central Powers). The Confederate States also declared war on both the Triple Alliance and the Big Five Powers with the opportunity to defeat the United States once again.
The first conflict started with the Austrian bombardment of Belgrade in September 1914. However, the siege had to be broken off because of Russian offensives poised to attack Transylvania. Germany then proceeded to attack France through Belgium, and Britain sent re-inforcements.
Germany signed a pact with the Qing Empire of China, but revolutions in which the Kuomintang was first born made it impossible for the Kaiser to send aid to its Asian ally. Japan then proceeded to attack German held territories in China at the Battle of Tsingtao in November 1914.
Serbia faced a massive invasion bu the Austro-Hungarian Empire with the Battle of Cer in 1915, in which Serbia won but suffered huge losses. However, Austrian, German and British mobilization had a huge effect on Serbia when they were defeated in October 1915, with Belgrade occupied. Serbia almost collapsed until Russian reinforcements prompted the opposing sides to fight the huge but ill equipped Russian army.
Croatia then staged an invasion of the Austrian half of the Austro-Hungarian Empire when the Austro-Hungarian army suffered a defeat by Russia in the Battle of the Masurian Lakes. However, Russian weaknesses that were facing its army proved to be futile when Germany scored major victories over Russia. In the Balkans, Croatia then suffered a defeat by the Austrian troops.
Britain then also invaded Croatia and Serbia from its overseas territory in Egypt through the Adriatic Sea. When Croatia and Serbia were on the verge of collapse, and Russia on the defensive, Japan sent troops to help with the Balkan Front. This move brought into conflict between Japan and the Ottoman Empire with the Japanese Navy defeating the Turkish Navy at the naval Battle of the Persian Gulf.
Japanese troops also scored victories against the Austro-Hungarian armies in the Serbo-Japanese offensive at the Battle of Kosovo in March of 1916.
1917 was the year of huge losses when the Russian Army had to defend their homeland.