King in the context of "Basileus"

Hades (/ˈheɪdiːz/; Ancient Greek: ᾍδης, romanized: Hā́idēs, Attic Greek: [háːi̯dεːs], later [háːdeːs]), in the ancient Greek religion and mythology, is the god of the dead and riches and the King of the underworld, with which his name became synonymous. Hades was the eldest son of Cronus and Rhea, although this also made him the last son to be regurgitated by his father. He and his brothers, Zeus and Poseidon, defeated, overthrew, and replaced their father's generation of gods, the Titans, and claimed joint sovereignty over the cosmos. Hades received the underworld, Zeus the sky, and Poseidon the sea, with the solid earth, which was long the domain of Gaia, available to all three concurrently. In artistic depictions, Hades is typically portrayed holding a bidentand wearing his helm with Cerberus, the three-headed guard-dog of the underworld, standing at his side.

Roman-era mythographers eventually equated the Etruscan god Aita,and the Roman gods Dis Pater and Orcus, with Hades, and merged all these figures into Pluto, a Latinisation of Plouton (Ancient Greek: Πλούτων, romanized: Ploútōn), itself a euphemistic title (meaning "the rich one") often given to Hades.

An emperor (from Latin: imperator, via Old French: empereor) is the (male) ruler of an empire. Empress, the female equivalent, may indicate an emperor's wife (empress consort), mother/grandmother (empress dowager/grand empress dowager), or a woman who rules in her own right and name (empress regnant or suo jure). Emperors are generally recognized to be of the highest monarchic honour and rank, surpassing king. In Europe, the title of Emperor has been used since the Middle Ages, considered in those times equal or almost equal in dignity to that of Pope due to the latter's position as visible head of the Church and spiritual leader of the Catholic part of Western Europe. The emperor of Japan is the only currently reigning monarch whose title is translated into English as "Emperor", although he no longer reigns over an empire.

Both emperors and kings are monarchs or sovereigns, both emperor and empress are considered monarchical titles. In as much as there is a strict definition of emperor, it is that an emperor has no relations implying the superiority of any other ruler and typically rules over more than one nation. Therefore, a king might be obliged to pay tribute to another ruler, or be restrained in his actions in some unequal fashion, but an emperor should in theory be completely free of such restraints. However, monarchs heading empires have not always used the title in all contexts—the British sovereign did not assume the title Empress of the British Empire even during the incorporation of India, though she was declared Empress of India.

A principality (or sometimes princedom) is a type of monarchical state or feudal territory ruled by a prince or princess. It can be either a sovereign state or a constituent part of a larger political entity. The term "principality" is often used to describe small monarchies, particularly those in Europe, where the ruler holds the title of prince or an equivalent.

Historically, principalities emerged during the Middle Ages as part of the feudal system, where local princes gained significant power within a king's domain. This led to political fragmentation and the creation of mini-states. Over time, many of these principalities consolidated into larger kingdoms and empires, while others retained their independence and prospered.

Tamar the Great (Georgian: თამარ მეფე, romanized: tamar mepe [ˈt̪ʰämäɾ ˈme̞pʰe̞], lit. 'King Tamar'; c. 1160 – 18 January 1213) reigned as the Queen of Georgia from 1184 to 1213, presiding over the apex of the Georgian Golden Age. A member of the Bagrationi dynasty, her position as the first woman to rule Georgia in her own right was emphasized by the title mepe ("king"), afforded to Tamar in the medieval Georgian sources.

Tamar was proclaimed heir and co-ruler by her reigning father George III in 1178, but she faced significant opposition from the aristocracy upon her ascension to full ruling powers after George's death. Tamar was successful in neutralizing this opposition and embarked on an energetic foreign policy aided by the decline of the hostile Seljuk Turks. Relying on a powerful military elite, Tamar was able to build on the successes of her predecessors to consolidate an empire which dominated the Caucasus until its collapse under the Mongol attacks within two decades after Tamar's death.

A queen regnant (pl.: queens regnant) is a female monarch, equivalent in rank, title and position to a king. She reigns suo jure (in her own right) over a realm known as a kingdom; as opposed to a queen consort, who is married to a reigning king; or a queen regent, who is the guardian of a child monarch and rules pro tempore in the child's stead or instead of her husband who is absent from the realm, be it de jure in sharing power or de facto in ruling alone. A queen regnant is sometimes called a woman king. A princess, duchess, or grand duchess regnant is a female monarch who reigns suo jure over a principality or (grand) duchy; an empress regnant is a female monarch who reigns suo jure over an empire.

A queen regnant possesses all the powers, such as they may be, of the monarchy, whereas a queen consort or queen regent shares her spouse's or child's rank and titles but does not share the sovereignty of her spouse or child. The husband of a queen regnant traditionally does not share the queen regnant’s rank, title, or sovereignty and usually holds a lower princely title. However, the concept of a king consort is not unheard of in both contemporary and historical periods.

Royal elections in Poland (Polish: wolna elekcja, lit. 'free election') were the elections of individual kings, rather than dynasties, to the Polish throne. Based on traditions dating to the very beginning of the Polish statehood, strengthened during the Piast and Jagiellon dynasties, they reached their final form in the Polish–Lithuanian Commonwealth period between 1572 and 1791. The "free election" was abolished by the Constitution of 3 May 1791, which established a constitutional-parliamentary monarchy.