Tsar in the context of "Dissolution of the Russian Empire"

Ivan Asen II, also known as John Asen II (Bulgarian: Иван Асен II, [iˈvan ɐˈsɛn ˈftɔri]; 1190s – May/June 1241), was Emperor (Tsar) of Bulgaria from 1218 to 1241. He was still a child when his father Ivan Asen I – one of the founders of the Second Bulgarian Empire – was killed in 1196. His supporters tried to secure the throne for him after his uncle, Kaloyan, was murdered in 1207, but Kaloyan's other nephew, Boril, overcame them. Ivan Asen fled from Bulgaria and settled in the Rus' principalities.

Boril could never strengthen his rule which enabled Ivan Asen to muster an army and return to Bulgaria. He captured Tarnovo and blinded Boril in 1218. Initially, he supported the full communion of the Bulgarian Church with the Papacy and concluded alliances with the neighboring Catholic powers, Hungary and the Latin Empire of Constantinople. He tried to achieve the regency for the 11-year-old Latin Emperor, Baldwin II, after 1228, but the Latin aristocrats did not support Ivan Asen. He inflicted a crushing defeat on Theodore Komnenos Doukas of the Empire of Thessalonica, in the Battle of Klokotnitsa in 1230. Theodore's empire soon collapsed and Ivan Asen conquered large territories in Macedonia, Thessaly and Thrace.

Caesar (Latin: [ˈkae̯.sar] English pl. Caesars; Latin pl. Caesares; in Greek: Καῖσαρ Kaîsar) is a title of imperial character. It derives from the cognomen of Julius Caesar. The change from being a surname to a title used by the Roman emperors can be traced to AD 68, following the fall of the Julio-Claudian dynasty. When used on its own, the title denoted heirs apparent, who would later adopt the title Augustus on accession. The title remained an essential part of the style of the emperors, and became the word for "emperor" in some languages, such as German (Kaiser) and Slavic (Tsar).

The Russian Empire was an empire that spanned most of northern Eurasia from its establishment in November 1721 until the proclamation of the Russian Republic in September 1917. At its height in the late 19th century, it covered about 22,800,000 km (8,800,000 sq mi), roughly one-sixth of the world's landmass, making it the third-largest empire in history, behind only the British and Mongol empires. It also colonized Alaska between 1799 and 1867. The empire's 1897 census, the only one it conducted, found a population of 125.6 million with considerable ethnic, linguistic, religious, and socioeconomic diversity.

From the 10th to 17th century, the Russians had been ruled by a noble class known as the boyars, above whom was the tsar, the absolute monarch. The groundwork of the Russian Empire was laid by Ivan III who ruled from 1462 to 1505, and greatly expanded his domain, established a centralized Russian national state, and secured independence against the Tatars. His grandson, Ivan IV (r. 1533–1584), became in 1547 the first Russian monarch to be crowned tsar of all Russia. Between 1550 and 1700, the Russian state grew by an average of 35,000 km (14,000 sq mi) per year. Peter I transformed the tsardom into an empire, and fought numerous wars that turned a vast realm into a major European power. He moved the Russian capital from Moscow to the new model city of Saint Petersburg, and led a cultural revolution that introduced a modern, scientific, rationalist, and Western-oriented system. Catherine the Great (r. 1762–1796) presided over further expansion of the Russian state by conquest, colonization, and diplomacy, while continuing Peter's policy of modernization. Alexander I (r. 1801–1825) helped defeat the militaristic ambitions of Napoleon and subsequently constituted the Holy Alliance, which aimed to restrain the rise of secularism and liberalism across Europe. Russia further expanded to the west, south, and east, strengthening its position as a European power. Its victories in the Russo-Turkish Wars were later checked by defeat in the Crimean War (1853–1856), leading to a period of reform and conquests in Central Asia. Alexander II (r. 1855–1881) initiated numerous reforms, most notably the 1861 emancipation of all 23 million serfs.

Simeon I the Great (Church Slavonic: цѣсар҄ь Сѷмеѡ́нъ А҃ Вели́къ; Bulgarian: цар Симеон I Велики, romanized: Simeon I Veliki [simɛˈɔn ˈpɤrvi vɛˈliki]; Greek: Συμεών Αʹ ὁ Μέγας, romanized: Sumeṓn prôtos ho Mégas) ruled over Bulgaria from 893 to 927, during the First Bulgarian Empire. Simeon's successful campaigns against the Byzantines, Magyars and Serbs led Bulgaria to its greatest territorial expansion ever, making it the most powerful state in contemporary Eastern and Southeast Europe. His reign was also a period of unmatched cultural prosperity and enlightenment later deemed the Golden Age of Bulgarian culture.

During Simeon's rule, Bulgaria spread over a territory between the Aegean, the Adriatic and the Black seas. The newly independent Bulgarian Orthodox Church became the first new patriarchate besides the Pentarchy, and Bulgarian Glagolitic and Cyrillic translations of Christian texts spread all over the Slavic world of the time. It was at the Preslav Literary School in the 890s that the Cyrillic alphabet was developed. Halfway through his reign, Simeon assumed the title of "emperor" (Tsar), having prior to that been styled "prince" (Knyaz).

Peter I (Church Slavonic: Петръ А҃; Bulgarian: Петър I; died 30 January 970) was the emperor (tsar) of Bulgaria from 27 May 927 to 969. Facing Bogomilism and rebellions by his brothers and also by Časlav Klonimirović early on in his reign, Peter secured more success later in life; he ensured the retreat of the invading Rus by inciting Bulgaria's allies, the Pechenegs, to attack Kiev itself. Traditionally seen as a weak ruler who lost land and prestige, recent scholarship challenges this view, emphasizing the empire's affluence and internal peace. Considered a good ruler during the Middle Ages, his name was adopted by later leaders trying to restore Bulgarian independence under Byzantine rule to emphasize legitimacy and continuity.

Boris II (Church Slavonic: Борисъ В҃; Bulgarian: Борис II; c. 931 – 977) was the emperor (tsar) of Bulgaria from 969 to 977 (in Byzantine captivity from 971).

Samuel (also Samoil or Samuil; Bulgarian: Самуил, pronounced [sɐmuˈiɫ]; Macedonian: Самоил/Самуил, pronounced [samɔˈiɫ/sɐmuˈiɫ]; Old Church Slavonic: Самоилъ; died 6 October 1014) was the Tsar (Emperor) of the First Bulgarian Empire from 997 to 6 October 1014. From 977 to 997, he was a general under Roman I of Bulgaria, the second surviving son of Emperor Peter I of Bulgaria, and co-ruled with him, as Roman bestowed upon him the command of the army and the effective royal authority. As Samuel struggled to preserve his country's independence from the Byzantine Empire, his rule was characterized by constant warfare against the Byzantines and their equally ambitious ruler Basil II.

In his early years, Samuel managed to inflict several major defeats on the Byzantines and to launch offensive campaigns into their territory. In the late 10th century, the Bulgarian armies conquered the Serb principality of Duklja and led campaigns against the Kingdoms of Croatia and Hungary. But from 1001, he was forced mainly to defend the Empire against the superior Byzantine armies. Samuel died of a heart attack on 6 October 1014, two months after the catastrophic battle of Kleidion. His successors failed to organize a resistance, and in 1018, four years after Samuel's death, the country capitulated, ending the five decades-long Byzantine–Bulgarian conflict.

Peter II, born Theodor, also known as Theodor-Peter (Bulgarian: Теодор-Петър; died in 1197), was the first emperor or tsar of the restored Bulgarian Empire from 1185 to 1197. He hails from the Byzantine theme of Paristrion, although his exact place and date of birth are unknown.

He and his younger brothers, Asen and Kaloyan, were mentioned as Vlachs in most foreign contemporaneous sources but they were probably of a mixed Vlach, Bulgarian, and Cuman origin. In 1185, Theodor and Asen approached the Byzantine Emperor Isaac II Angelos in Thrace, demanding an estate in the Balkan Mountains. After the Emperor refused and humiliated them, they decided to incite a rebellion, taking advantage of the discontent that a new tax had caused among the Bulgarians and Vlachs. To convince their compatriots to join them, they had native prophets declare that Saint Demetrius of Thessalonica had abandoned the Romans in favour of the Bulgarians and Vlachs. Before the end of the year, Theodor was crowned Emperor of Bulgaria, taking the name Peter and adopting the insignia used only by emperors.

Ivan Asen I, also known as Asen I or John Asen I (Bulgarian: Иван Асен I; died in 1196), was emperor or tsar of Bulgaria from 1187/1188 to 1196 as co-ruler with his elder brother, Peter II. Hailing from the Byzantine theme of Paristrion, his exact place and date of birth are unknown. Most contemporaneous chronicles describe Asen and his brothers, Theodor (Peter) and Kaloyan, as Vlachs but they were probably of mixed Bulgarian, Cuman and Vlach ancestry.

In 1185, Asen and Theodor went to see the Byzantine Emperor Isaac II Angelos in Thrace to demand an estate in the Balkan Mountains. After the Emperor refused and humiliated them, the brothers persuaded their Bulgarian and Vlach compatriots to rise up against the Byzantine Empire. Before the end of the year, Theodor was crowned Emperor of Bulgaria, taking the name Peter. After Isaac II defeated them in early 1186, Asen and Peter fled north over the Danube but returned in the autumn, accompanied by Cuman reinforcements. They captured Paristrion and began pillaging the nearby Byzantine territories.

The Byzantine–Bulgarian war of 913–927 (Bulgarian: Българо–византийска война от 913–927) was fought between the Bulgarian Empire and the Byzantine Empire for more than a decade. Although the war was provoked by the Byzantine emperor Alexander's decision to discontinue paying an annual tribute to Bulgaria, the military and ideological initiative was held by Simeon I of Bulgaria, who demanded to be recognized as Tsar and made it clear that he aimed to conquer not only Constantinople but the rest of the Byzantine Empire, as well.

In 917, the Bulgarian army dealt a crushing defeat to the Byzantines at the Battle of Achelous, resulting in Bulgaria's total military supremacy in the Balkans. The Bulgarians again defeated the Byzantines at Katasyrtai in 917, Pegae in 921 and Constantinople in 922. The Bulgarians also captured the important city of Adrianople in Thrace and seized the capital of the Theme of Hellas, Thebes, deep in southern Greece. Following the disaster at Achelous, Byzantine diplomacy incited the Principality of Serbia to attack Bulgaria from the west, but this assault was easily contained. In 924, the Serbs ambushed and defeated a small Bulgarian army on its way to Serbia, provoking a major retaliatory campaign that ended with Bulgaria's annexation of Serbia at the end of that year.