He did this on 5 October (though celebrated on 22 September, as Bulgaria remained officially on the Julian Calendar until 1916) in the St Forty Martyrs Church in Veliko Tarnovo.

The Bulgarian army inflicted several crushing defeats on the Ottoman forces and advanced threateningly against Constantinople, while the Serbs and the Greeks took control of Macedonia.

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.

When Germany pledged to restore the boundaries of the Treaty of San Stefano, Bulgaria, boasting the largest army in the Balkans, declared war on Serbia in October 1915.

However, the war quickly became unpopular among the majority of Bulgarians, who endured severe economic hardship and resented fighting alongside their fellow Orthodox Christians while allied with the Muslim Ottomans.

[10] After World War I, Bulgaria had already lost a significant amount of territory, including its coast to the Aegean Sea with Dede Agach (Alexandroupoli), which was crucial for the Bulgarian economy, as well as the Western Outlands.

The Agrarian Party primarily represented disgruntled peasants, particularly those dissatisfied with the government in Sofia during Ferdinand's corrupt reign, which exploited and stole from the peasantry.

On the other hand, the Bulgarian Communist Party drew support mainly from the intelligentsia and urban professionals, with its primary base consisting of the poorest peasants and minorities.

Bulgaria was burdened with substantial war reparations to Yugoslavia and Romania and had to contend with the issue of refugees, as pro-Bulgarian Macedonians were forced to leave Yugoslav Macedonia.

He abolished the mercantile monopoly on grain and replaced it with a state syndicate, dismantled large urban and rural estates and sold the surplus to the poor, introduced compulsory labor laws to alleviate post-war unemployment, implemented a progressive income tax, and made secondary education mandatory.

All aspects of this radical reform policy were designed to eliminate "noxious" classes such as lawyers, usurers, and merchants, distribute wealth and responsibilities more equitably across society, and improve the living standards of landless and poor peasants.

In foreign policy, Stamboliyski officially renounced Bulgaria's territorial claims, which he associated with a standing army, monarchy, and large government expenditures—phenomena that peasants considered outdated.

Therefore, in 1921, Stamboliyski initiated a two-year period of severe repression against the IMRO; by 1923, Bulgaria and Yugoslavia agreed at the Nis Convention to collaborate in combating extremism.

Bulgaria, having been compelled to reduce its armed forces after World War I, saw IMRO leaders gain control over much of the border area with Yugoslavia.

Stamboliyski responded with mass arrests, an intensified campaign against IMRO terrorism, a purge of his own fractured and notoriously corrupt party, and called for new parliamentary elections.

This triggered a nationalist reaction, and on 9 June there was a coup organized by the armed forces under General Ivan Valkov's Military Union with support from the Tsar and other right-wing elements of the Tsardom after the AP controlled 87% of Parliament in the elections that year.

The September Uprising began in 1923, after the 9 June coup d'état, when Alexander Stamboliyski was planning to capture Pazardzhik with his sympathizers to restore his power, which was quickly disrupted by the Bulgarian Army.

In foreign policy, Lyapchev tried unsuccessfully to improve the terms of British and French reparations from the First World War and to bring Bulgaria out of its post-war diplomatic isolation.

After participating in the Bulgarian coup d'état of 1934, Zveno supporters declared their intention to immediately form an alliance with France and to seek the unification of Bulgaria into an Integral Yugoslavia.

Boris claimed that domination of the new subranie by pro-government representatives justified his non-party system, although the People's Constitutional Bloc seated over sixty delegates.

[19] With the rise of the "King's government" in 1935, Bulgaria entered an era of prosperity and astounding growth, which deservedly qualifies it as the Golden Age of the Third Bulgarian Kingdom.

Kyoseivanov's Premiership oversaw the trials of the instigators of the 1934 military coup and also concluded pacts with Yugoslavia and Greece as Nazi Germany undertook a policy of economic isolation of the Balkans.

However, it was clear that the central geopolitical position of Bulgaria in the Balkans would inevitably lead to strong external pressure from both World War II factions.

[41] The persecution began in 1941 with the passing of anti-Jewish legislation and culminated in March 1943 with the arrest and deportation of almost all[42] – 11,343 – of the Jews living in Bulgarian-occupied regions of Northern Greece, Yugoslav Macedonia and Pirot.

Upon becoming aware of the impending plans members of parliament led by Dimitar Peshev pressured the interior minister to revoke the initial deportation order, while public protests and interventions by prominent figures, notably Bulgarian Orthodox Church bishops Stefan of Sofia and Kiril of Plovdiv, persuaded the Tsar first to stop the deportation temporarily in March 1943, and two months later to postpone it indefinitely.

Before the First Balkan War, Bulgaria didn't have control over the main parts of the Rhodope Mountains, which included settlements such as Smolyan, Kardzhali etc.

During World War I, Bulgaria joined in 1915 on the side of the Central Powers and gained a large amount of land from the Kingdom of Serbia, which included Macedonia and the sheer extensiveness around Niš.

Overall, education reached more of the lower classes than anywhere else in Eastern Europe[citation needed], but on the downside all too many students obtained degrees in the liberal arts and other abstract subjects and could not find work anywhere except in the government bureaucracy.

While more successful than the rest of Eastern Europe, Bulgarian agriculture still suffered from the handicaps of backward technology and especially rural overpopulation and scattered plots (due to the traditional practice of a peasant dividing his land equally among all surviving sons).

However, they were able to switch with little difficulty to garden crops and tobacco in contrast to other countries where the peasantry suffered harder due to continued reliance on maize and wheat.