Task: Question Answering
Input (English): Context: A monarchy is a form of government in which a group, usually a family called the dynasty, embodies the country's national identity and one of its members, called the monarch, exercises a role of sovereignty. The actual power of the monarch may vary from purely symbolic (crowned republic), to partial and restricted ("constitutional" monarchy), to completely autocratic ("absolute" monarchy). Traditionally and in most cases, the monarch's post is inherited and lasts until death or abdication, but there are also elective monarchies where the monarch is elected. Each of these has variations: in some elected monarchies only those of certain pedigrees are, whereas many hereditary monarchies impose requirements regarding the religion, age, gender, mental capacity, and other factors. Occasionally this might create a situation of rival claimants whose legitimacy is subject to effective election. Finally, there have been cases where the term of a monarch's reign is either fixed in years or continues until certain goals are achieved: an invasion being repulsed, for instance. Thus there are widely divergent structures and traditions defining monarchy.
Monarchy was the most common form of government until the 19th century, but it is no longer prevalent. Where it exists, it is now usually a constitutional monarchy, in which the monarch retains a unique legal and ceremonial role, but exercises limited or no official political power: under the written or unwritten constitution, others have governing authority. Currently, 47 sovereign nations in the world have monarchs acting as heads of state, 19 of which are Commonwealth realms that recognise Queen Elizabeth II as their head of state. All European monarchies are constitutional ones, with the exception of the Vatican City which is an elective monarchy, but sovereigns in the smaller states exercise greater political influence than in the larger. The monarchs of Cambodia, Japan, and Malaysia "reign, but do not rule" although there is considerable variation in the degree of authority they wield. Although they reign under constitutions, the monarchs of Brunei, Morocco, Oman, Qatar, Saudi Arabia and Swaziland appear to continue to exercise more political influence than any other single source of authority in their nations, either by constitutional mandate or by tradition., Li Jiancheng (  ) ( 589 -- July 2 , 626 ) , formally Crown Prince Yin (  , literally , `` the hidden crown prince '' ) , nickname Pishamen (  ) , was a crown prince of the Chinese dynasty Tang Dynasty . He was the oldest son of the founding emperor Emperor Gaozu ( Li Yuan ) and therefore was designated crown prince after the founding of the dynasty in 618 . However , although he himself was fairly capable as a general , he was overshadowed by the contributions of his younger brother Li Shimin the Prince of Qin , and the brothers contended for power for years , with Li Jiancheng aided by another younger brother , Li Yuanji the Prince of Qi . In 626 , Li Shimin , fearing that Li Jiancheng and Li Yuanji were about to kill him , laid an ambush for them at Xuanwu Gate outside the palace and killed them . Li Shimin then effectively forced Emperor Gaozu to yield the throne to him ( as Emperor Taizong ) ., The Sui Dynasty was a short-lived imperial dynasty of China of pivotal significance. The Sui unified the Northern and Southern dynasties and reinstalled the rule of ethnic Han Chinese in the entire China proper, along with sinicization of former nomadic ethnic minorities within its territory. It was succeeded by the Tang dynasty, which largely inherited its foundation., In the history of Europe, the Middle Ages or medieval period lasted from the 5th to the 15th century. It began with the fall of the Western Roman Empire and merged into the Renaissance and the Age of Discovery. The Middle Ages is the middle period of the three traditional divisions of Western history: classical antiquity, the medieval period, and the modern period. The medieval period is itself subdivided into the Early, High, and Late Middle Ages., Xi'an, formerly romanized as Sian, and also known as Chang'an before the Ming dynasty, is the capital of Shaanxi Province, People's Republic of China. It is a sub-provincial city located in the center of the Guanzhong Plain in Northwest China. One of the oldest cities in China, Xi'an is the oldest of the Four Great Ancient Capitals, having held the position under several of the most important dynasties in Chinese history, including Western Zhou, Qin, Western Han, Sui, and Tang. Xi'an is the starting point of the Silk Road and home to the Terracotta Army of Emperor Qin Shi Huang., A crown prince or crown princess is the heir apparent to the throne in a royal or imperial monarchy. The wife of a crown prince is also titled "crown princess"., Li Yuanji () (603  July 2, 626), formally Prince La of Chao (), more commonly known by the title of Prince of Qi (), nickname Sanhu (), was an imperial prince of the Chinese Tang Dynasty. He was a son of the dynasty's founder Emperor Gaozu of Tang (Li Yuan), and in the intense rivalry developed between his older brothers Li Jiancheng the Crown Prince and Li Shimin the Prince of Qin, he sided with Li Jiancheng and often advocated drastic actions against Li Shimin, including assassination. In 626, Li Shimin, fearing that Li Jiancheng and Li Yuanji were about to kill him, laid an ambush for them at Xuanwu Gate outside the palace and killed them. Li Shimin then effectively forced Emperor Gaozu to yield the throne to him (as Emperor Taizong)., The Han dynasty was the second imperial dynasty of China (206 BC220 AD), preceded by the Qin dynasty (221206 BC) and succeeded by the Three Kingdoms period (220280 AD). Spanning over four centuries, the Han period is considered a golden age in Chinese history. To this day, China's majority ethnic group refers to itself as the "Han people" and the Chinese script is referred to as "Han characters".
It was founded by the rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han, and briefly interrupted by the Xin dynasty (923 AD) of the former regent Wang Mang. This interregnum separates the Han dynasty into two periods: the Western Han or Former Han (206 BC  9 AD) and the Eastern Han or Later Han (25220 AD)., Emperor Gaozu of Tang (8 April 566  25 June 635), born Li Yuan, courtesy name Shude, was the founder of the Tang Dynasty of China, and the first emperor of this dynasty from 618 to 626. Under the Sui dynasty, Li Yuan was the governor in the area of modern-day Shanxi, and was based in Taiyuan., The Tang dynasty was an imperial dynasty of China preceded by the Sui dynasty and followed by the Five Dynasties and Ten Kingdoms period. It is generally regarded as a high point in Chinese civilization, and a golden age of cosmopolitan culture. Its territory, acquired through the military campaigns of its early rulers, rivaled that of the Han dynasty, and the Tang capital at Chang'an (present-day Xi'an) was the most populous city in the world., An emperor (through Old French "empereor" from ) is a monarch, usually the sovereign ruler of an empire or another type of imperial realm. Empress, the female equivalent, may indicate an emperor's wife ("empress consort"), mother ("empress dowager"), or a woman who rules in her own right ("empress regnant"). Emperors are generally recognized to be of a higher honour and rank than kings. In Europe the title of Emperor was, since the Middle Ages, considered 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 Western Europe. The Emperor of Japan is the only currently reigning monarch whose title is translated into English as "Emperor"., Subject: li jiancheng, Relation: father, Options: (A) discovery (B) election (C) emperor gaozu of han (D) emperor gaozu of tang (E) pivotal (F) taizong (G) wang mang (H) zhou
Output (English): emperor gaozu of tang