The reason why the Russian army retreated from Bucharest was because the battle line was too long, because Bulgaria controlled Dobroga, it was difficult for the Russian army to use the Danube for transportation with confidence, and the Austro-Hungarian army threatened the Russian flank from the northwest, so they chose to retreat strategically.

The reason for the retreat was also because they saw a mistake by the Greek-Bulgarian coalition forces, who threw the vast majority of their forces into the frontal battlefield, leaving the Dobroga region defenses empty. At the entrance to the Danube, they also maintained tens of thousands of defenses, but in the rear they were very empty.

So the Russian army adjusted its strategy, the main force withdrew to Galatz upstream, advanced in the direction of Tulcha, completely controlled the mouth of the Danube, and then the Russian army opened a channel for communication from the sea. The Russian army has sea supremacy, and the Austro-Hungarian Navy has been defeated, because the main force of the Austro-Hungarian Navy has always been in Fum, not in the closed Black Sea. As a result, after the start of the war, the straits would not have been opened without the consent of Russia, and the Austro-Hungarian Navy would not have access to the Black Sea. Of course, in the same way, the Russian Navy cannot get out of the Black Sea without the consent of other countries.

The Russian army has mastered the sea supremacy, and of course it is impossible to limit itself to the seizure of the mouth of the Danube. Finding the rear of the Greek-Bulgarian coalition empty, they made a bold decision to use their naval supremacy to transport the convoy to capture Dobroga, and they chose to land at Varna. Close to the Balkan Mountains, it is the largest port in Bulgaria and has a long history, where the Greeks founded the city-state of Odyssas 2,600 years ago.

Some rivers originating from the Balkan Mountains and flowing into the sea from Varna Bay are coastal plains surrounded by hundreds of thousands of acres of fertile land.

But the defense here is very lax, there are some fortifications, but the troops are very small, only more than 30,000 militia to defend. The Russian Navy cannot break through the fortress and cannot bombard the fortress battery, but it can land nearby, detour behind the battery, and capture the fortress with the army, and the navy is only responsible for blockade and containment.

After adjusting their strategy, the Russian army quickly captured Varna, and then quickly reinforced its army from here, and soon advanced to the Balkans and the Danube, blocking the Greek-Bulgarian coalition army in Wallachia. On the other hand, the Russian army that went south from Galati also successfully captured Tulcha, and the Russian army from the north and south advanced against each other, and in less than a month, it controlled the entire Dobroga, from the Balkans to the mouth of the Danube, and now it is in the hands of the Russian army.

This extremely unfavorable situation led the British, although they did not support the Greek seizure of Wallachia, but did not organize Greece to receive aid from the British. At the same time, Britain began to lobby Greece to negotiate with Austria-Hungary to resolve the Wallachian question, and Britain tried to make peace with the mud and favored Austria-Hungary. It hoped that Wallachia would be given a degree of autonomy, similar to that of the Kingdom of Hungary, but to a lesser extent than Hungary.

But Austria-Hungary would rather lose Wallachia than do so, and gave Wallachia autonomy, Bohemia, Bosnia, Dalmatia, the nine principalities within the empire, and the three kingdoms, I am afraid that they will all ask for autonomy.

Greece told Britain at this time that Bulgaria, which was on the side of the coalition forces, might withdraw from the war because the Russian army had captured important Bulgarian cities, and Greece might also withdraw from the war. Or the United Kingdom of Greece will have to negotiate with Russia, and Greece hopes that Britain will provide political and diplomatic support to Greece. Resist the strategic security of Russia's expansion in the direction of Greece and encircle the countries of Western Europe.

Previously, the United Kingdom of Greece and Bulgaria was very troublesome, and for this war, Bulgaria was more active, because they were full of ambitions for the Danube territory, but the Kingdom of Greece reacted coldly, Greece's finances were under great pressure, and the problem of so many refugees was not completely solved, so another war was going on, and Greece could not get real benefits at all. If the war is won, Bulgaria may expand its territory, and if it loses, Greece will follow the land and pay reparations.

It was easy to convince the parliament by various means, and of course the king's control was quite strong, and if the parliament did not agree, he intended to use the powers granted to the king by the constitution. After convincing Greece, it joined the war. At this time, the real trouble is that Dobroga will not be able to get the Bulgarian political forces to hand it over, because this area, in the era of the Bulgarian Empire, was the relatively rich territory of Bulgaria, and Bulgaria, a country like the poor and rich, values every inch of land.

So the king chose to let the Russian army occupy Dobroga, at this time Bulgaria was directly threatened by the Russian army, starting a war, possibly losing more territory, peace talks, and surrendering Dobroga.

If Bulgaria is willing to die more, then let them fight, the irrationality of nationalism will require dry blood to sober up. Sure enough, when the Russians captured Varna, the Bulgarian army urged the king to order them to withdraw and regain the lost territory. After weighing it, the king asked the Bulgarian army of 200,000 to retreat from the front line and counterattack the Russian army.

The Bulgarians have always been fierce, and during the Ottoman Empire, they launched many uprisings. Although they actually speak the same language as Russia, they are all Slavs. But the Russians occupied their territory, and they fought without mercy. After this war, for Zhou Chenggong, Russia's influence on Bulgaria as a Slav would disappear completely.

Stimulated by nationalism, coupled with formal training, and a close follow of European military concepts and British weapons, they are on a par with the Russian army. However, after losing more than 30,000 men, the king ordered the defense of the Balkan Mountains to prevent the Russian army from continuing to advance into the heart of Bulgaria.

The Greek army was deployed in the area of Bucharest, but the situation was a little delicate at this time, the Austro-Hungarian army advanced south to the periphery of Bucharest, and the Russian army made a comeback and drove nearby, and the three-way attack 1.3 million troops were concentrated within 100 kilometers around Bucharest, at this time the Russian army may attack the Greek army or the Austro-Hungarian army, the Austro-Hungarian army may attack the Russian army, and the Greek army may also attack the Greek army, and the Greek army has no alliance with the two sides at the same time, but everyone has found out, Whoever strikes first will be exposed to third parties.

In this strange three-legged situation, all three parties were very cautious not to take the initiative to attack, and they all guarded against attacks from two directions at the same time.

The three parties almost divided the Duchy of Wallachia, with the smallest but best of Greek control, located around Bucharest.

Russia occupied the area north of the Buze River and east of the Danube; Austria-Hungary took control of the area west of the Oort River.

The three sides are in a state of standoff, and whoever attacks first is likely to suffer the biggest defeat.

At this time, Austria-Hungary and Russia, which had more than enough stamina, began to gain the upper hand, because they could mobilize more troops. Austria-Hungary expanded the army to one million, balanced the forces, and divided the financial burden. Expand the forces directly under the empire, with the Imperial Parliament territories bearing seventy-five percent of military expenditures, and Hungary bearing two-fifths of military expenditures. However, the Royal Hungarian Army would fight alone, under the command of a Hungarian officer, but would obey the orders of the Imperial Command. The Russians did not mobilize, but their allies, the Ural Army, announced their entry into the war. In this way, the active forces of the Russian army and the Ural army have an army of 2 million, and the maximum strength that can be used for front-line operations can reach 1.7 million.

It was always difficult to reach an agreement in the negotiations between Austria-Hungary and the Greeks, and in the Wallachian direction it was impossible to fight jointly. At this time, Greece also mobilized a new army, increasing the number of troops to half a million. In addition, there were 200,000 Bulgarian troops, totaling up to 700,000 people, which Greece could not organize on its own, not because of a lack of men, but because of a lack of money. The military aid provided by Britain allows Greece to do this, but it must also be aligned with British interests.

Britain allowed Greece to make contact with Russia, and in the "negotiations" between Greece and Russia, Greece miraculously allowed Russia to accept the conquest of Wallachia, which would place the Russian-occupied Wallachia under Greek control. However, Russia insisted on refusing to cede Dobroga, and the Ural army that came to Russia's aid took over, while the main Russian army moved to other battlefields.

At this time, the Russian army had already made it clear that it was going to fight with Austria-Hungary. Austria-Hungary did not care about face, and had already begun to turn to Prussia, Britain and other countries for help, hoping to get military assistance, hoping to form a military alliance, and so on.

The agreement reached between Greece and Russia at this time allowed Greece to even form a temporary alliance with Russia and launch an attack on Austria-Hungary.

Britain believes that even if Britain and Prussia aid Austria at this time, it will not be easy for Austria to win this war, because Russia has not yet carried out a general mobilization, and once they mobilize, the combined strength of Prussia and Austria may not be able to surpass the Russian army, because the Russian army will still be supported by two million Ural troops.

Britain lobbied Austria to accept the reality of losing the principality of Moldova, so as to keep Transylvania, with the combat effectiveness shown by the Russian army in this war, once the war is lost, Austria-Hungary will lose more than just a principality of Moldova. As for the Duchy of Wallachia, Britain hoped that Austria-Hungary would maintain the status quo with the Greeks.

The King of Greece convened a meeting of the heads of government of Greece, Bulgaria and Wallachia and conveyed the conditions put forward by Russia. Russia would never cede Dobroga, but was willing to return eastern Wallachia.

In this case, the principality of Wallachia was naturally willing, but Bulgaria was not, and the Greeks were not concerned with their own affairs.

The prime ministers of Wallachia and Bulgaria quarreled fiercely, Bulgaria believed that they had entered the war because they had helped Wallachians, and because of the war, the Russian army had seized a large amount of territory, and it was also the best port to the sea in the country, so Wallachia believed that it should not accept Russia's demands, but should unite the three parties and continue to fight with Russia.