He was adopted by Claudius in AD 50 as official heir to the throne.

Alexander Balas (), ruler of the Greek Seleucid kingdom in 150 – 146 BC, was a native of Smyrna of humble origin, but gave himself out to be the son of Antiochus IV Epiphanes and Laodice IV and heir to the Seleucid throne.

The general impression was that, as much as the senate was packed with men devoted to the royal couple and the government obtained a large majority at the general elections, King Alexander would not hesitate any longer to proclaim Queen Draga's brother as the heir to the throne.

As Alexander left no surviving children the heir to the throne was his unborn child by Queen Yolande.

* Willem-Alexander, Prince of Orange ( born 1967 ), the eldest child of Queen Beatrix and Prince Claus and heir apparent to the throne of the Kingdom of the Netherlands

Afonso, born in Lisbon, was the rightful heir to the Portuguese throne.

* Infante Juan Carlos Teresa Silvestre Alfonso of Spain ( 1913 – 1993 ), named heir to the throne and Count of Barcelona, whose son is the current King, Juan Carlos I of Spain.

Finally, when a Serbian backed organization assassinated the heir of the Austro-Hungarian throne, causing the 1914 July Crisis, nobody could stop the conflict and the First World War broke out.

Banquo's loyalty to Macbeth, rather than Malcolm, after Duncan's death makes him a passive accomplice in the coup: Malcolm, as Prince of Cumberland, is the rightful heir to the throne and Macbeth a usurper.

At the age of three, Catherine was betrothed to Prince Arthur, heir to the English throne, and they married in 1501, but Arthur died five months later.

At an early age, Catherine was considered a suitable wife for Arthur, Prince of Wales, the eldest son of Henry VII of England and heir to the throne, due to the English ancestry she inherited from her mother Queen Isabella I of Castile.

It would also have given a male heir an indisputable claim to the throne.

Because all of the five children he fathered with his first and fourth wife were daughters, he would have no lawful male heir to his throne.

He was slated to become the heir, but did not succeed to the throne, dying childless in 1377, 7 years after King Casimir.

( Sons by secondary consorts were usually recognized as imperial princes, too, and could be recognized as heir to the throne if the empress did not give birth to an heir.

If the empress did not give birth to an heir, the emperor could take a concubine, and the son he had by that concubine would be recognized as heir to the throne.

After the fall of the Byzantine Empire, the legitimate heir to the throne, Andreas Palaiologos, willed away his claim to Ferdinand and Isabella in 1503.

Edward now became the undisputed heir to the throne.

Her silence, however, strengthened her own political security: she knew that if she named an heir, her throne would be vulnerable to a coup ; she remembered that the way " a second person, as I have been " had been used as the focus of plots against her sister, Queen Mary.

She feared that the French planned to invade England and put Mary, Queen of Scots, who was considered by many to be the heir to the English crown, on the throne.

Mountbatten's qualification for offering advice to this particular heir to the throne was unique ; it was he who had arranged the visit of King George VI and Queen Elizabeth to Dartmouth Royal Naval College on 22 July 1939, taking care to include the young Princesses Elizabeth and Margaret in the invitation, but assigning his nephew, Cadet Prince Philip of Greece, to keep them amused while their parents toured the facility.

When Buretsu died, Kanamura recommended Keitai at his age of 58 as a possible heir to the Yamato throne.

As the first-born son of King Priam and Queen Hecuba, a descendant of Dardanus, who lived under Mount Ida, and of Tros, the founder of Troy, he was a prince of the royal house and the heir apparent to his father's throne.

Early in 1539, Frederick was married to Elizabeth of Mansfeld, but he died shortly afterwards, leaving no prospect of an heir.

This was the outcome of the Russo-Swedish War from 1741 to 1743 where the Russian Empress made the imposition of her relative Adolf Frederick as the heir to the Swedish Throne, to succeed Frederick I who lacked legitimate issue, as a peace condition.

When King Conrad III died without adult heir in 1152, Frederick also succeeded him, taking both German royal and Imperial titles.

* 1186 – Henry VI, the son and heir of the Holy Roman Emperor Frederick I, marries Constance of Sicily.

As his father then ruled as Margrave of Brandenburg-Ansbach ( from 1457 also as Margrave of Brandenburg-Kulmbach ), he was born at the Hohenzollern residence of Ansbach in Franconia, where he spent his childhood years until in 1466 he received the call to Brandenburg as presumed heir by his uncle Elector Frederick II.

At the time, the union between Sweden and Norway under one monarch, together with the fact that King Frederick VII of Denmark had no male heir, gave rise to the idea of reuniting the countries of the Kalmar Union, except for Finland.

Succession to the duchies of Schleswig and Holstein was disputed ; they were claimed by Christian IX ( Frederick VII's heir as King ) and by Frederick von Augustenburg ( a German duke ).

* 1268 – Conradin, the last legitimate male heir of the Hohenstaufen dynasty of Kings of Germany and Holy Roman Emperors, is executed along with his companion Frederick I, Margrave of Baden by Charles I of Sicily, a political rival and ally to the hostile Roman Catholic church.

In this period, the Holy See was engaged in a conflict with Manfred of Sicily, the illegitimate son and designated heir of Holy Roman Emperor Frederick II of Hohenstaufen, but whom papal loyalists, the Guelfs, called " the usurper of Naples ".

Frederick II's heir Manfred was immersed in these struggles.

Upon Sophia's death, her eldest son Elector George Louis of Brunswick-Lüneburg ( 1660 – 1727 ) became heir presumptive in her place, and weeks later, succeeded Queen Anne as George I. Sophia's daughter Sophia Charlotte of Hanover ( 1668 – 1705 ) married Frederick I of Prussia, from whom the later Prussian Kings descend.

* 1125: Lothair of Supplinburg, duke of Saxony, is elected Holy Roman Emperor instead of the nearest heir, Frederick of Swabia, beginning the great struggle of Guelf and Ghibelline.

* 1268 – October 29 – Conradin, the last legitimate male heir of the Hohenstaufen dynasty of Kings of Germany and Holy Roman Emperors, is executed along with his companion Frederick I, Margrave of Baden by Charles I of Sicily, a political rival and ally to the hostile Catholic church.

Frederick Tilney: Henry's older brother ( the presumed heir to the Northanger estate ), an officer in the army who enjoys pursuing flirtations with pretty girls who are willing to offer him some encouragement ( though without any ultimate serious intent on his part ).

* October 29 – Conradin, the last legitimate male heir of the Hohenstaufen dynasty of Kings of Germany and Holy Roman Emperors, is executed along with his companion Frederick I, Margrave of Baden by Charles I of Sicily, a political rival and ally to the hostile Roman Catholic church.

The early deaths of his two older brothers, Frederick Augustus ( 1721 ), who was stillborn, and Joseph Augustus ( 1728 ), made him the heir to the throne.

Charles Frederick, son of Frederick IV, Duke of Holstein-Gottorp ( a cousin of Charles XII ) and Hedvig Sophia, daughter of Charles XI of Sweden, was the Swedish heir since 1702.

In 1218, after Berthold died without an heir, Bern was made a free imperial city by the Goldene Handfeste of Holy Roman Emperor Frederick II.

Cadets of France's princes étrangers began to affect similar usage but when, for example, the House of La Tour d ' Auvergne's ruling dukes of Bouillon, attempted to use the same style, it was initially resisted by historians such as Père Anselme – who, however, willingly recognized use of territorial titles, i. e. he accepts that the ducal heir apparent is known as prince de Bouillon, but would record in 1728 only that the heir's cousin, the comte d ' Oliergues was " known as the Prince Frederick " (" dit le prince Frédéric ").

Following the death of his father in 1897, he was heir to the grand-ducal throne of his cousin Frederick II.

John William Friso was a great-grandson of Frederick Henry and was appointed heir in William III's will.