The Second Bulgarian Empire (Bulgarian: Второ българско царство, Vtorо Bălgarskо Tsarstvo) was a medieval Bulgarian state that existed between 1185 and 1396. A successor to the First Bulgarian Empire, it reached the peak of its power under Tsars Kaloyan and Ivan Asen II before gradually being conquered by the Ottomans in the late 14th and early 15th centuries. It was succeeded by the Principality and later Kingdom of Bulgaria in 1878.
Until 1256, the Second Bulgarian Empire was the dominant power in the Balkans, defeating the Byzantine Empire in several major battles. In 1205 Emperor Kaloyan defeated the newly established Latin Empire in the Battle of Adrianople. His nephew Ivan Asen II defeated the Despotate of Epiros and made Bulgaria a regional power again. During his reign, Bulgaria spread from the Adriatic to the Black Sea and the economy flourished. In the late 13th century, however, the Empire declined under constant invasions by Mongols, Byzantines, Hungarians, and Serbs, as well as internal unrest and revolts. The 14th century saw a temporary recovery and stability, but also the peak of Balkan feudalism as central authorities gradually lost power in many regions. Bulgaria was divided into three parts on the eve of the Ottoman invasion.
Despite strong Byzantine influence, Bulgarian artists and architects created their own distinctive style. In the 14th century, during the period known as the Second Golden Age of Bulgarian culture, literature, art and architecture flourished. The capital city Tarnovo, which was considered a "New Constantinople", became the country's main cultural hub and the centre of the Eastern Orthodox world for contemporary Bulgarians. After the Ottoman conquest, many Bulgarian clerics and scholars emigrated to Serbia, Wallachia, Moldavia, and Russian principalities, where they introduced Bulgarian culture, books, and hesychastic ideas.
The name most frequently used for the empire by contemporaries was Bulgaria, as the state called itself. During Kaloyan's reign, the state was sometimes known as being of both Bulgarians and Vlachs. Pope Innocent III and other foreigners such as the Latin Emperor Henry mentioned the state as Bulgaria and the Bulgarian Empire in official letters.
In modern historiography, the state is called the Second Bulgarian Empire, Second Bulgarian Tsardom, or the Second Bulgarian Kingdom to distinguish it from the First Bulgarian Empire. An alternative name used in connection with the pre-mid 13th century period is the Empire of Vlachs and Bulgars; variant names include the Vlach–Bulgarian Empire, the Bulgarian–Wallachian Empire, or the Romanian–Bulgarian Empire; the latter name was used exclusively in Romanian historiography.
However, Arabic chronicles from the 13th century had used only the name of Wallachia instead of Bulgaria and gave the Arabic coordinates of Wallachia and specified that Walachia was named "al-Awalak" and the dwellers "ulaqut" or "ulagh"