Emperor in the context of "Queen Victoria"

The emperor of Japan is the hereditary monarch and head of state of Japan. The emperor is defined by the Constitution of Japan as the symbol of the Japanese state and the unity of the Japanese people, his position deriving from "the will of the people with whom resides sovereign power". The Imperial Household Law governs the line of imperial succession. Pursuant to his constitutional role as a national symbol, and in accordance with rulings by the Supreme Court of Japan, the emperor is personally immune from prosecution. By virtue of his position as the head of the Imperial House, the emperor is also recognized as the head of the Shinto religion, which holds him to be the direct descendant of the sun goddess Amaterasu. According to tradition, the office of emperor was created in the 7th century BC, but the first historically verifiable emperors appear around the 5th or 6th centuries AD.

The role of the emperor of Japan has historically alternated between a largely ceremonial symbolic role and that of an actual imperial ruler. Since the establishment of the first shogunate in 1192, the emperors of Japan have rarely taken on a role as supreme battlefield commander, unlike many Western monarchs. Japanese emperors have nearly always been controlled by external political forces, to varying degrees. Between 1192 and 1867, the shōguns, or their shikken regents in Kamakura (1203–1333), were the de facto rulers of Japan, although they were nominally appointed by the emperor. After the Meiji Restoration in 1868, the emperor was the embodiment of all sovereign power in the realm, as enshrined in the Meiji Constitution of 1889. Since the enactment of the 1947 constitution, the role of emperor has been relegated to that of a ceremonial head of state without even nominal political powers. The emperor is the head of the Japanese honors system, conferring orders, decorations, medals, and awards in the name of the state and on behalf of its people in accordance with the advice of the Cabinet.

Basileus (Ancient Greek: βασιλεύς) is a Greek term and title that has signified various types of monarchs throughout history. In the English-speaking world, it is perhaps most widely understood to mean 'monarch', referring to either a 'king' or an 'emperor'. The title was used by sovereigns and other persons of authority in ancient Greece (especially during the Hellenistic period), the Byzantine emperors, and the kings of modern Greece. The name Basileios (Basil), deriving from the term basileus, is a common given name in the Eastern Orthodox Church and Syriac Orthodox Church for the Maphrian.

The feminine forms are basileia (βασίλεια), basilissa (βασίλισσα), basillis (βασιλίς), or the archaic basilinna (βασιλίννα), meaning 'queen' or 'empress'. The related term basileia (βασιλεία) has meanings such as 'sovereignty', 'royalty', 'kingdom', 'reign', 'dominion' and 'authority'.

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).

An empire is a realm controlled by an emperor or an empress and divided between a dominant center and subordinate peripheries. The center of the empire (sometimes referred to as the metropole) has political control over the peripheries. Within an empire, different populations may have different sets of rights and may be governed differently. The word "empire" derives from the Roman concept of imperium. Narrowly defined, an empire is a sovereign state whose head of state uses the title of "emperor" or "empress"; but not all states with aggregate territory under the rule of supreme authorities are called "empires" or are ruled by an emperor; nor have all self-described empires been accepted as such by contemporaries and historians (the Central African Empire of 1976 to 1979, and some Anglo-Saxon kingdoms in early England being examples).

There have been "ancient and modern, centralized and decentralized, ultra-brutal and relatively benign" empires. An important distinction has been between land empires made up solely of contiguous territories, such as the Achaemenid Empire, Roman Empire, the Mongol Empire, or the Russian Empire; and those - based on sea-power - which include territories that are remote from the 'home' country of the empire, such as the Dutch colonial empire, the Empire of Japan, the Chola Empire or the British Empire.

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).

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.

Kaloyan or Kalojan, also known as Ivan I, Ioannitsa or Johannitsa (Bulgarian: Калоян, Йоаница; c. 1170 – October 1207), the Roman Slayer, was emperor or tsar of Bulgaria from 1196 to 1207. He was the younger brother of Theodor and Asen, who led the anti-Byzantine uprising of the Bulgarians and Vlachs in 1185. The uprising ended with the restoration of Bulgaria as an independent state. He spent a few years as a hostage in Constantinople in the late 1180s. Theodor, crowned Emperor Peter II, made him his co-ruler after Asen was murdered in 1196. A year later, Peter was also murdered, and Kaloyan became the sole ruler of Bulgaria.

After the successful siege of Varna in 1201 against the Byzantine Empire, the defenders and governors of the city were tied and thrown into the moat of the fortress walls and covered with dirt by the Bulgarians. After they were buried alive in this way, Kaloyan declared himself a Bulgarian avenger, adopting the moniker "the Romanslayer" by analogy with the emperor Basil II the Bulgar Slayer, who defeated and blinded a Bulgarian army of 15,000 people.