The history of Ottoman Bulgaria spans over 500 years, beginning in the late 14th century, with the Ottoman conquest of smaller kingdoms from the disintegrating Second Bulgarian Empire. After the Russo-Turkish War of 1878, Bulgaria was gradually liberated from the Ottoman Empire, and, in 1908, Bulgaria declared its independence from the Ottoman Empire.

The brutal suppression of the Bulgarian April Uprising of 1876 and the public outcry it caused across Europe led to the Constantinople Conference, where the Great Powers tabled a joint proposal for the creation of two autonomous Bulgarian vilayets, largely corresponding to the ethnic boundaries drawn a decade earlier with the establishment of the Bulgarian Exarchate.

The sabotage of the Conference, by either the British or the Russian Empire (depending on theory), led to the Russo-Turkish War (1877–1878), whereby the much smaller Principality of Bulgaria, a self-governing, but functionally independent Ottoman vassal state was created. In 1885 the Ottoman autonomous province of Eastern Rumelia unified through a bloodless coup with the Principality of Bulgaria.

Administrative organization

The Ottomans reorganised the Bulgarian territories, dividing them into several vilayets, each ruled by a Sanjakbey or Subasi accountable to the Beylerbey. Significant parts of the conquered land were parcelled out to the Sultan's followers, who held it as benefices or fiefs (small timar, medium zeamet and large hass) directly from him, or from the Beylerbeys.C. M. Woodhouse, Modern Greece: A Short History, p. 101. This category of land could not be sold or inherited but reverted to the Sultan when the fiefholder died. The lands were organised as private possessions of the Sultan or Ottoman nobility, called "mülk", and also as an economic base for religious foundations, called vakιf, as well as other people. The system was meant to make the army self-sufficient and to continuously increase the number of Ottoman cavalry soldiers, thus both fuelling new conquests and bringing conquered countries under direct Ottoman control.

From the 14th century until the 19th century Sofia was an important administrative centre in the Ottoman Empire. It became the capital of the beylerbeylik of Rumelia (Rumelia Eyalet), the province that administered the Ottoman lands in Europe (the Balkans), one of the two together with the beylerbeylik of Anatolia. It was the capital of the important Sanjak of Sofia as well, including the whole of Thrace with Plovdiv and Edirne, and part of Macedonia with Thessaloniki and Skopje.

The Danube Vilayet was a first-level administrative division (vilayet) of the Ottoman Empire from 1864 to 1878 with a capital in Ruse. In the late 19th century it reportedly had an area of 34,120 square miles (88,400 km2) and incorporated the Vidin Eyalet, Silistra Eyalet and Niš Eyalet.

Legal status and taxation Christians paid disproportionately higher taxes than Muslims, including poll tax, jizye, in lieu of military service. According to İnalcık, jizye was the single most important source of income (48 per cent) to the Ottoman budget, with Rumelia accounting for the lion's share, or 81 per cent of the revenues. By the early 1600s, the timar system had virtually been abolished, and almost all land had been divided into estates (arpalik) granted to senior Ottoman dignitaries as a form of tax farming, which created conditions for severe exploitation of taxpayers by unscrupulous land holders.

According to Radishev, overtaxation became a particularly poignant issue after jizye collection in most of the country was taken over by the Six Divisions of Cavalry.

Bulgarians also paid a number of other taxes, including a tithe ("yushur"), a land tax ("ispench"), a levy on commerce, and various irregularly collected taxes, products and corvees ("avariz"). Generally, the overall tax burden on the rayah (i.e., non-Muslims), was twice as high as that on Muslims.

Christians faced a number of other restrictions: they were barred from testifying against Muslims in inter-faith legal disputes. Even though they were free to perform their own religious rituals, this had to be done in a manner that was inconspicuous to Muslims, i.e., loud prayers or bell ringing were forbidden. They were barred from certain professions, from riding horses, from wearing certain colours or from carrying weapons.

Nevertheless, there were specific categories of rayah who were exempt from nearly all such restrictions, such as the Dervendjis, who guarded important passes, roads, bridges, etc., ore-mining settlements such as Chiprovtsi, etc. Some of the most important Bulgarian cultural and economic centres in the 19th century owe their development to a former dervendji status, for example, Gabrovo, Dryanovo, Kalofer, Panagyurishte, Kotel, Zheravna. Similarly, Christians living on wakf holdings were subject to lower tax burden and fewer restrictions.

Religion

The Ottoman Empire's greatest advantage compared to other colonial powers, the millet system and the autonomy each denomination had within legal, confessional, cultural and family matters, nevertheless, largely did not apply to Bulgarians and most other Orthodox peoples on the Balkans, as the independent Bulgarian Patriarchate was destroyed and all Bulgarian Orthodox dioceses were subjected to the rule of the Ecumenical Patriarch in Constantinople and made part of Rum millet (Greek Orthodox millet). Thus, instead of helping Christian Bulgarians maintain their customs and cultural identity, the millet system actually promoted their assimilation.

Bulgarian ceased to be a literary language, the higher clergy was invariably Greek, and the Phanariotes started making persistent efforts to hellenise Bulgarians as early as the early 1700s. It was only after the struggle for church autonomy in the mid-1800s and especially after the Bulgarian Exarchate was established by a firman of Sultan Abdülaziz in 1870 that this policy was reversed.

Non-Muslims did not serve in the Sultan's army. The exception to this were some groups of the population with specific statute, usually used for auxiliary or rear services, and the infamous blood tax (кръвен данък), also known as devşirme, where young Christian Bulgarian boys were taken from their families, enslaved and converted to Islam and later employed either in the Janissary military corps or the Ottoman administrative system. The boys were picked from one in forty households. They had to be unmarried and, once taken, were ordered to cut all ties with their family.

While a minority of authors have argued that "some parents were often eager to have their children enrol in the Janissary service that ensured them a successful career and comfort", scholarly consensus leans very much the other way. Christian parents are described to have resented the forced recruitment of their children, and would beg and seek to buy their children out of the levy. Many different ways of avoiding the devshirme are mentioned, including: marrying the boys at the age of 12, mutilating them or having both father and son convert to Islam. In 1565, the practice led to a revolt in Albania and Epirus, where the inhabitants killed the recruiting officials.

It was not rare for the boys to attempt to preserve their faith and some recollection of their homeland and their families. For example, Stephan Gerlach writes:

When Greek scholar Janus Lascaris visited Constantinople in 1491, he met many Janissaries who not only remembered their former religion and their native land but also favoured their former coreligionists. One of them told him that he regretted having left the religion of his fathers and that he prayed at night before the cross which he kept carefully concealed.

Spread of Islam

Islam in Bulgaria spread through both colonisation with Muslims from Asia Minor and conversion of native Bulgarians. The Ottomans' mass population transfers began in the late 1300s and continued well into the 1500s. The first community settled in present-day Bulgaria was made up of Tatars who willingly arrived to begin a settled life as farmers, the second one a tribe of nomads that had run afoul of the Ottoman administration. Both groups settled in the Upper Thracian Plain, in the vicinity of Plovdiv. Another large group of Tatars was moved by Mehmed I to Thrace in 1418, followed by the relocation of more than 1000 Turkoman families to Northeastern Bulgaria in the 1490s. At the same time, there are records of at least two forced relocations of Bulgarians to Anatolia, one right after the fall of Veliko Tarnovo and a second one to İzmir in the mid-1400s. The goal of this "mixing of peoples" was to quell any unrest in the conquered Balkan states, while simultaneously getting rid of troublemakers in the Ottoman backyard in Anatolia.

However, Ottomans never pursued or practiced forced Islamisation of the Bulgarian population, as had earlier been claimed by Communist Bulgarian historiography. According to scholarly consensus, conversion to Islam was voluntary as it offered Bulgarians religious and economic benefits. According to Thomas Walker Arnold, Islam was not spread by force in the areas under the control of the Ottoman Sultan.The preaching of Islam: a history of the propagation of the Muslim faith By Sir Thomas Walker Arnold, pg. 135-144 A 17th-century author said: Meanwhile he (the Turk) wins (converts) by craft more than by force, and snatches away Christ by fraud out of the hearts of men. For the Turk, it is true, at the present time compels no country by violence to apostatise; but he uses other means whereby imperceptibly he roots out Christianity...

Thus, in a number of cases, conversion to Islam can be said to have been the result of tax coercion, due to the much lower tax burden on Muslims. While some authors have argued that other factors, such as desire to retain social status, were of greater importance, Turkish writer Halil İnalcık has referred to the desire to stop paying jizya as a primary incentive for conversion to Islam in the Balkans, and Bulgarian researcher Anton Minkov has argued that it was one among several motivating factors.

Two large-scale studies of the causes of adoption of Islam in Bulgaria, one of the Chepino Valley by Dutch Ottomanist Machiel Kiel, and another one of the region of Gotse Delchev in the Western Rhodopes by Evgeni Radushev reveal a complex set of factors behind the process. These include: pre-existing high population density owing to the late inclusion of the two mountainous regions in the Ottoman system of taxation; immigration of Christian Bulgarians from lowland regions to avoid taxation throughout the 1400s; the relative poverty of the regions; early introduction of local Christian Bulgarians to Islam through contacts with nomadic Yörüks; the nearly constant Ottoman conflict with the Habsburgs from the mid-1500s to the early 1700s; the resulting massive war expenses that led to a sixfold increase in the jizya rate from 1574 to 1691 and the imposition of a war-time avariz tax; the Little Ice Age in the 1600s that caused crop failures and widespread famine; heavy corruption and overtaxation by local landholders—all of which led to a slow, but steady process of Islamisation until the mid-1600s when the tax burden became so unbearable that most of the remaining Christians either converted en masse or left for lowland areas.

These factors had an impact on the entire country. Due to them, the population of Ottoman Bulgaria is presumed to have dropped twofold from a peak of approx. 1.8 million (1.2 million Christians and 0.6 million Muslims) in the 1580s to approx. 0.9 million in the 1680s (450,000 Christians and 450,000 Muslims), after growing steadily from a base of approx. 600,000 (450,000 Christians and 150,000 Muslims) in the 1450s.

First revolts and the Great Powers