Royal intermarriage

[3] It could also enhance the prospect of territorial acquisition for a dynasty by procuring legal claim to a foreign throne, or portions of its realm (e.g., colonies), through inheritance from an heiress whenever a monarch failed to leave an undisputed male heir.

In other parts of the world royal intermarriage was less prevalent and the number of instances varied over time, depending on the culture and foreign policy of the era.

[8] Other examples of historical, mythical and contemporary royal intermarriages throughout Africa include: Several Egyptian pharaohs married the daughters of neighbouring kings to secure peace and form alliances.

Not to mention the Ptolemaic Kingdom, the last (and longest) dynasty to rule all of Egypt before its incorporation into the Roman Republic, who were infamous for their inbreeding in the form of sibling marriages.

[23] Other consorts of Assyrian monarchs, such as Naqiʾa, Ešarra-ḫammat,[24] Banitu (who was perhaps brought to Assyria as a hostage after Tiglath-Pileser's conquest of Babylon)[25] might also have been of Babylonian origin.

[37][38] In return, the king granted the Vietnamese the right to establish settlements in Mô Xoài (now Bà Rịa), in the region of Prey Nokor—which they colloquially referred to as Sài Gòn, and which later became Ho Chi Minh City.

[72] Han Durang (Yelu Longyun) was the father of Queen dowager of State Chen, who was the wife of General Geng Yanyi and buried with him in his tomb in Zhaoyang in Liaoning.

[78] To maintain the ethnic purity of the ruling dynasty, after the Kangxi Period (1662–1722), emperors and princes were forbidden to marry non-Manchu and non-Mongol wives.

[79] The Manchu imperial Aisin Gioro clan practiced marriage alliances with Han Chinese Ming generals and Mongol princes.

[93] The Goryeo dynasty had a history of incestuous marriage within the royal family in its early years, starting from Gwangjong, the fourth king, who married his half-sister Queen Daemok.

[102] According to the Shoku Nihongi, an imperially commissioned record of Japanese history completed in 797, Emperor Kanmu who ruled from 781 to 806 was the son of a Korean concubine, Takano no Niigasa, who was descended from King Muryeong of Baekje, one of the Three Kingdoms of Korea.

Rome thought that such marriages promoted stability among their client states and prevented petty local wars that would disturb the Pax Romana.

[104] Glaphyra of Cappadocia was known to have contracted three such royal intermarriages: with Juba II&I, King of Numidia and Mauretania, Alexander of Judea and Herod Archelaus, Ethnarch of Samaria.

[105] Other examples from the Ancient Roman era include: Though some emperors, such as Justin I and Justinian I, took low-born wives,[n 1] dynastic intermarriages in imperial families were not unusual in the Byzantine Empire.

One early example is the marriage of John Doukas Vatatzes with Constance, the daughter of Emperor Frederick II of the Holy Roman Empire, to seal their alliance.

[112] Later in the century, Andronikos II Palaiologos agreed to marital alliances with Ghazan of the Ilkhanate and Toqta and Uzbeg of the Golden Horde, which were quickly followed by their marriages to his daughters.

[n 2] Theodora Megale Komnene, daughter of John IV, was married to Uzun Hassan, lord of the Aq Qoyunlu, to seal an alliance between the Empire and the so-called White Sheep.

Although the alliance failed to save Trebizond from its eventual defeat, and despite being a devout Christian in a Muslim state, Theodora did manage to exercise a pervasive influence both in the domestic and foreign actions of her husband.

[115] Their grandson Ismail I was the founder of the Safavid dynasty of Iran Though usually made to strengthen the position of the empire, there are examples of interdynastic marriages destabilising the emperor's authority.

On her marriage to Louis XIV of France, Maria Theresa, daughter of Philip IV of Spain, was forced to renounce her claim to the Spanish throne.

The marriage contract of Philip II of Spain and Mary I of England, for example, stipulated that the maternal possessions, as well as Burgundy and the Low Countries, were to pass to any future children of the couple, whereas the remaining paternal possessions (including Spain, Naples, Sicily, Milan) would first of all go to Philip's son Don Carlos, from his previous marriage to Maria Manuela of Portugal.

The 1572 wedding in Paris of the French princess Margaret of Valois to the leader of France's Huguenots, Henry III of Navarre, was ostensibly arranged to effect a rapprochement between the nation's Catholics and Protestants, but proved a ruse for the St. Bartholomew's Day massacre.

When in 1926 Astrid of Sweden married Leopold III of Belgium, it was agreed that her children would be raised as Catholics but she was not required to give up Lutheranism, although she did eventually choose to convert in 1930.

However, as dynasties approached absolutism and sought to preserve loyalty among competing members of the nobility, most eventually distanced themselves from kinship ties to local nobles by marrying abroad.

During the era of absolutism, this practice contributed to the notion that it was socially, as well as politically, disadvantageous for members of ruling families to intermarry with their subjects and pass over the opportunity for marriage into a foreign dynasty.

Among Europe's current kings, queens and heirs apparent, only Alois, Hereditary Prince of Liechtenstein married a member of a foreign dynasty, as did the abdicated Juan Carlos I of Spain.

Early marriages, such as that of Abd al-Aziz ibn Musa and Egilona at the turn of the 8th century, was thought to help establish the legitimacy of Muslim rule on the Iberian Peninsula.

Christian consorts of Ottoman sultans include Theodora Kantakouzene of Byzantium, Kera Tamara of Bulgaria and Olivera Despina of Serbia.

By this time, the Ottomans had consolidated their power in the area and absorbed or subjugated many of their former rivals, and so marriage alliances were no longer seen as important to their foreign policy.

Among the aliʻi, the ruling class, marriage between blood relatives of the first degree was believed to produce children with the highest rank under the kapu system, equal to that of the gods.