Question: When did the monarch of Norway ascend to the throne?

Context paragraphs:
Chakkaphat Phaen Phaeo: Chakkaphat Phaen Phaeo (also Sai Tia Kaphut or Xainyachakkaphat) (1442–1480) reigned as King of Lan Xang, succeeding the "Maha Devi" after an interregnum of several years.  He was born in 1415 as Prince Vong Buri, the youngest son of King Samsenthai by Queen Nan Keo Yot Fa daughter of King Intharacha of Ayutthaya.  When he came of age he was appointed as Governor of Vientiane.  He was invited to ascend the throne several times during the succession dispute orchestrated by the "Maha Devi", but refused.  The Council of Ministers finally persuaded him to become king in 1441, after they had failed to find any other candidate.  He still refused to be crowned and avoided the ceremony for many years.  Finally bowing to custom in 1456, he was formally coroneted and assumed the reign name and title of "Samdach Brhat-Anya Chao Sanaka Chakrapati Raja Phen-Phaeo Bhaya Jayadiya Kabuddha".  The regnal name is significant because it translates in Pali to "cakkavattin," meaning "Universal Buddhist Monarch."  Vong Buri, and the court, were claiming enough political and religious power to unify the kingdom, and warn surrounding kingdoms, despite the upheaval caused by the "Maha Devi" and interregnum in Lan Xang from 1428-1442.

Monarch: A monarch is a sovereign head of state in a monarchy.  A monarch may exercise the highest authority and power in the state, or others may wield that power on behalf of the monarch.  Typically a monarch either personally inherits the lawful right to exercise the state's sovereign rights (often referred to as "the throne" or "the crown") or is selected by an established process from a family or cohort eligible to provide the nation's monarch.  Alternatively, an individual may become monarch by conquest, acclamation or a combination of means.  A monarch usually reigns for life or until abdication.

Harald V of Norway: Harald V (] ; born 21 February 1937) is the King of Norway, having ascended the throne following the death of his father on 17 January 1991.

Civil war era in Norway: The civil war era in Norway (Norwegian: "borgerkrigstiden") is the history of Norway between 1130 and 1240.  During this time a series of civil wars were fought between rival kings and pretenders to the throne.  The reasons for the war was the weak succession of King Sigurd the Crusader, leaving the country between his bastard son Magnus and his alleged (but uncertain) brother, Harald Gillekrist, who were on bad terms long before King Sigurd died.  The goal of the warring parties was always to put their man on the throne, starting with the death of King Sigurd the Crusader in 1130, a supposedly adored monarch.  In the first decades of the civil wars, alliances shifted and centered on the person of a king or pretender, but eventually, towards the end of the 12th century, two rival parties emerged, known as the Birkebeiner and the Bagler.  After these two parties were reconciled in 1217, a more ordered system of government centered on the king was gradually able to bring an end to the frequent risings.  The failed rising of duke Skule Bårdsson in 1240 was the final event of the civil war era.

Norse Federation: The Norse Federation (Norwegian: "Nordmanns-Forbundet" ) is a Norwegian non-profit organization that was founded it 1907, and is under the patronage of the monarch of Norway, currently King Harald V.  The organization states that its purpose is to "unit[e] friends of Norway throughout the world".  s of 2010 , the organization has approximately 3500 members.  It publishes a periodical which is named "The Norseman".

Qvarqvare III Jaqeli: Qvarqvare III Jaqeli (Georgian: ყვარყვარე III ჯაყელი ) (died 1535) was a Georgian ruling Prince and Atabeg of Samtskhe-Saatabago during 1518–1535.  Member of the Jaqeli family and son of Atabeg Kaikhosro I Jaqeli.  His failure to capture the throne at the death of his father Kaikhosro may have been caused by the ambition of his uncle Mzetchabuki, who had seized Atabeg's title from him.  Despite of this Mzetchabuk Jaqeli declared Qvarqare as his successor.  During his uncle's reign Qvarqvare actively involved in state affairs.  In 1515 ill Mzetchabuk resigned from the throne and came to the Monastery as a monk.  Qvarqvare couldn't ascend to the Meskhetian throne, because his second uncle Manuchar I had revolted.  Qvarqvare went to Safavid Persia, became vassal of Shah Ismail I and lived at his court in Tabriz until his accession.  In 1518 Qvarqvare commanded Qizilbash army and invaded Samtskhe.  Persians dethroned Manuchar I and placed Qvarqvare on the throne.  Manuchar invited Ottomans to fight against Safavids and overthrow his nephew, but Qvarqvare's forces defeated him at the battle near Erzurum, after which Manuchar escaped to the Ottoman empire. During Qvarqvare's reign Persian influence on Samtskhe was growing day by day.  Because of that Turks greatly damaged the country and especially it's southwestern region.  Meskhetian lords had recognized that under Qvarqvare's rule Samtskhe would finally turn to the Enemy's hands.  They made an alliance with the Georgian kings, Bagrat III of Imereti and Luarsab I of Kartli to end up Jaqelian rule and protect Samtskhe from dominant muslim empires (Ottomans and Safavids.  In 1535 King Bagrat III invaded Samtskhe.  He defeated and captured Qvarqvare III at the Battle of Murjakheti near Akhalkalaki, Georgians had annexed Principality of Samtskhe.  Qvarqvare died in prison.  A few years later, his survived youngest son Kaikhosro II requested Ottomans to expel Imeretian and Kartlian forces from Samtskhe.  In 1545, at the Battle of Sokhoista, Kaikhosro defeated Bagrat III, after which he reinstated his legitimate throne.  Samtskhe became vassal of the Ottoman empire.  Qvarqvare III's descendants ruled Samtskhe-Saatabago (until 1628) and then Childir Eyalet until 1820s.

Throne: A throne is the seat of state of a potentate or dignitary, especially the seat occupied by a sovereign on state occasions; or the seat occupied by a pope or bishop on ceremonial occasions.  "Throne" in an abstract sense can also refer to the monarchy or the Crown itself, an instance of metonymy, and is also used in many expressions such as "the power behind the throne".  The expression "ascend (mount) the throne" takes its meaning from the steps leading up to the dais or platform, on which the throne is placed, being formerly comprised in the word's significance.

Throne Chairs of Norway: The Throne Chairs of Norway (Norwegian Bokmål: singular "Norges tronstol", plural "-stoler"; Norwegian Nynorsk: singular "Noregs tronstol", plural "-stolar") are the physical representations of the Throne of the Kingdom of Norway.  One stands in the building of the Parliament in Oslo, the political capital of Norway, where it is used in a political context.  The other stands in Trondheim, the religious capital of Norway, where it was used in a religious context.  A lesser known is the Throne Chair in the Council Chamber in the Royal Palace.  In addition to the Throne Chairs, there are two coronation chairs (Bokmål and Nynorsk: "kroningstol"), which are also located in Trondheim.  Between 1671 and 1814, the Throne Chair of Denmark was de facto also Norway's.

Throne of England: The Throne of England is the English term used to identify the throne of the Monarch of England.  In an abstract sense, "Throne of England" refers metonymically to the office of monarch, and monarchy itself.  The term "Throne of Great Britain" has been used in reference to Sovereign's Throne in the House of Lords, from which a monarch gives his or her speech at the State opening of Parliament.

Vajiralongkorn: Maha Vajiralongkorn Bodindradebayavarangkun (Thai: มหาวชิราลงกรณ บดินทรเทพยวรางกูร , rtgs: "Mahawachiralongkon Bodinthrathepphayawarangkun" ,  ] ; born 28 July 1952) is the King of Thailand, since 2016.  He is the only son of King Bhumibol Adulyadej and Queen Sirikit.  In 1972, at the age of 20, he was made crown prince by his father.  After his father's death on 13 October 2016, he was expected to succeed to the throne of Thailand but asked for time to mourn before taking the throne.  He accepted the throne on the night of 1 December 2016 but will not be crowned formally until after the cremation of his father, expected to be on 26 October 2017.  His father Bhumibol's coronation took place four years after his accession.  The government retroactively declared his reign to have begun on 13 October 2016, upon his father's death.  As the tenth monarch of the Chakri Dynasty, he is also styled as Rama X.  At the age of 64, Vajiralongkorn is the oldest Thai monarch to ascend to the throne.

Supporting paragraphs: Norse Federation Harald V of Norway
Answer: 17 January 1991