Third Bulgarian State
The Treaty of San Stefano was signed on March 3, 1878 and set up an autonomous Bulgarian principality on the territories of the Second Bulgarian Empire, including the regions of Moesia, Thrace and Macedonia, though the state was de jure only autonomous but de facto functioned independently. However, trying to preserve the balance of power in Europe and fearing the establishment of a large Russian client state on the Balkans, the other Great Powers were reluctant to agree to the treaty. As a result, the Treaty of Berlin (1878), under the supervision of Otto von Bismarck of the German Empire and Benjamin Disraeli of Britain, revised the earlier treaty, and scaled back the proposed Bulgarian state. The new territory of Bulgaria was limited between the Danube and the Stara Planina range, with its seat at the old Bulgarian capital of Veliko Turnovo and including Sofia. This revision left large populations of ethnic Bulgarians outside the new country and defined Bulgaria's militaristic approach to foreign affairs and its participation in four wars during the first half of the 20th century. Bulgaria entered a war against Serbia in 1885, only seven years after its restoration. The war resulted in a Bulgarian victory and incorporation of the semi-autonomous Ottoman territory of Eastern Rumelia into the Principality.
Bulgaria emerged from Turkish rule as a poor, underdeveloped agricultural country, with little industry or tapped natural resources. Most of the land was owned by small farmers, with peasants comprising 80% of the population of 3.8 million in 1900. Agrarianism was the dominant political philosophy in the countryside, as the peasantry organized a movement independent of any existing party. In 1899, the Bulgarian Agrarian Union was formed, bringing together rural intellectuals such as teachers with ambitious peasants. It promoted modern farming practices, as well as elementary education. The government promoted modernization, with special emphasis on building a network of elementary and secondary schools. By 1910, there were 4,800 elementary schools, 330 lyceums, 27 high schools, and 113 vocational schools. From 1878 to 1933, France funded numerous libraries, research institutes, and Catholic schools throughout Bulgaria. In 1888, a university was established. It was renamed the University of Sofia in 1904, where the three faculties of history and philology, physics and mathematics, and law produced civil servants for national and local government offices. It became the center of German and Russian intellectual, philosophical and theological influences. The first decade of the century saw sustained prosperity, with steady urban growth. The capital of Sofia grew by a factor of 600% - from 20,000 population in 1878 to 120,000 in 1912, primarily from peasants who arrived from the villages to become laborers tradesman and office seekers. Macedonians used Bulgaria as a base, beginning in 1894, to agitate for independence from the Ottoman Empire. They launched a poorly planned uprising in 1903 that was brutally suppressed, and led to tens of thousands of additional refugees pouring into Bulgaria.
The Balkan Wars
In the years following the achievement of independence, Bulgaria was becoming increasingly militarized and was often referred to as "the Balkan Prussia", with regard to its desire to revise the Treaty of Berlin through warfare. The partition of territories in the Balkans by the Great Powers without regard to ethnic composition led to a wave of discontent not only in Bulgaria, but also in its neighbouring countries. In 1911, Nationalist Prime Minister Ivan Geshov formed an alliance with Greece and Serbia to jointly attack the Ottomans and revise the existing agreements around ethnic lines. In February 1912 a secret treaty was signed between Bulgaria and Serbia and in May 1912 a similar agreement was sealed with Greece. Montenegro was also brought into the pact. The treaties provided for the partition of Macedonia and Thrace between the allies, although the lines of partition were left dangerously vague. After the Ottoman Empire refused to implement reforms in the disputed areas, the First Balkan War broke out in October 1912 at a time when the Ottomans were tied down in a major war with Italy. The allies in Libya easily defeated the Ottomans and seized most of its European territory.
Bulgaria sustained the heaviest casualties of any of the allies and in any case tried to seize the largest share of the spoils. The Serbs in particular did not agree and refused to vacate any of the territory they had seized in northern Macedonia, saying that the Bulgarian army had failed to accomplish its pre-war goals at Adrianople (to capture it without Serbian help) and that the pre-war agreement on the division of Macedonia had to be revised. Some circles in Bulgaria inclined toward going to war with Serbia and Greece on this issue. In June 1913, Serbia and Greece formed a new alliance against Bulgaria. The Serbian Prime Minister Nikola Pasic told Greece it could have Thrace if Greece helped Serbia keep Bulgaria out of Serbian part of Macedonia and the Greek Prime Minister Eleftherios Venizelos agreed. Seeing this as a violation of the pre-war agreements, and discreetly encouraged by Germany and Austria-Hungary, Tsar Ferdinand declared war on Serbia and Greece and the Bulgarian army attacked on June 29. The Serbian and the Greek forces were initially on the retreat on the western border, but soon took the upper hand and forced Bulgaria to retreat. The fighting was very harsh, with many casualties, especially during the key Battle of Bregalnitsa. Soon Romania entered the war and attacked Bulgaria from the north. The Ottoman Empire saw this as an opportunity to regain the territories lost to the Bulgarian advancement and also attacked from the south-east.
The Second Balkan War was now lost for Bulgaria, which sued for peace. It was forced to relinquish most of Macedonia to Serbia and Greece, while the revived Ottomans retook Adrianople. Romania took southern Dobruja. The two Balkan wars had greatly destabilised Bulgaria, stopping its steady economic progress and costing 58,000 dead and over 100,000 wounded. However, the revanchist demand to recover the bulk of Macedonia remained powerful.
World War I
In the aftermath of the Balkan Wars Bulgarian opinion turned against Russia and the Western powers, whom the Bulgarians felt had done nothing to help them. The government of Vasil Radoslavov aligned Bulgaria with the German Empire and Austria-Hungary, even though this meant becoming an ally of the Ottomans, Bulgaria's traditional enemy. But Bulgaria now had no claims against the Ottomans, whereas Serbia, Greece and Romania (allies of Britain and France) held lands perceived in Bulgaria as Bulgarian.
Bulgaria sat out the first year of World War I recuperating from the Balkan Wars. Germany and Austria realized they needed Bulgaria's help in order to defeat Serbia militarily, and thereby open supply lines from Germany to Turkey, and bolster the Eastern Front against Russia. Bulgaria insisted on major territorial gains, especially Macedonia, which Austria was reluctant to grant until Berlin insisted. Bulgaria also negotiated with the Allies, who offered somewhat less generous terms. The Tsar decided to go with Germany and Austria and signed an alliance with them in September 1915, along with a special Bulgarian-Turkish arrangement. It envisioned that Bulgaria would dominate the Balkans after the war. Bulgaria, which had the largest army in the Balkans, declared war on Serbia in October 1915. Britain, France and Italy responded by declaring war on Bulgaria. In alliance with Germany, Austria-Hungary and the Ottomans, Bulgaria won military victories against Serbia and Romania, occupying much of Macedonia (taking Skopje in October), advancing into Greek Macedonia, and taking Dobruja from Romania in September 1916. Thus Serbia was knocked out of the war, and Turkey was rescued from collapse. By 1917, Bulgaria fielded more than a quarter of its 4.5 million population in a 1,200,000-strong army, and inflicted heavy losses on Great Britain (Doiran), France (Monastir), the Russian Empire (Dobrich) and the Kingdom of Romania (Tutrakan).
In April and May 1918, the war in Europe had ended with British and French capitulation. Under the Treaty of Mitte (November 1919) Bulgaria gained nearly all of its Macedonian territory, and had to received Southern Dobruja as well as the southern part of Northern Dobruja in the Treaty of Bucharest(May 1918). Bulgarians generally refer to the results of the treaty as "Justice for the National Catastrophe".
Elections in November 1923 gave the Democratic Alliance a large majority and Aleksandar Tsankov formed a reactionary government. An extreme right-wing government, backed by the army and VMRO, which waged a White terror against Agrarians and Communists. In 1926, after the brief War of the Stray Dog, the Tsar persuaded Tsankov to resign, a more moderate government under Andrey Lyapchev took office and an amnesty was proclaimed, although the Communists remained banned. A popular alliance, including the re-organised Agrarians, won the elections of 1931 under the name "Popular Bloc".
In May 1934 a coup took place, removing the Popular Bloc from power and establishing an authoritarian military régime headed by Kimon Georgiev. A year later, Tsar Ferdinand managed to remove the military régime from power, restoring a form of parliamentary rule (without the re-establishment of the political parties) and under his own strict control. The Tsar's regime proclaimed neutrality, but gradually Bulgaria gravitated into alliance with Germany and Fascist Italy.