William the Conqueror was a bastard and I have heard him being referred to as William the Bastard by a Beefeater on a tour in the Tower of London.

Are there any other examples of bastards becoming kings in history? I'd be especially interested if any bastards from common bloodlines ever became kings.

  • 1
    William I most certainly was a bastard as well as The Conqueror. Commented Apr 18, 2014 at 1:43
  • 4
    William's mother was a tanner's daughter, which is pretty common, compared to other recognised bastards usually made with other nobles e.g. Gruffydd son of Llewellyn the Great. Gruffydd was heir to the throne of Wales, but his father named Dafydd heir, to please the English as he had an English mother. William I was actually teased by rivals about his origins, e.g. They hung skins from a wall under siege "you stink like a tannery"
    – Duncan
    Commented Apr 18, 2014 at 5:44
  • 3
    I'd rule out William, not because of Bastardy but because he won the crown by conquest as an adult.
    – Oldcat
    Commented Aug 15, 2014 at 21:17
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    There's a slight subtext to the beefeater's phrase. Supposedly William should NOT be referred to as Conqueror in the City of London because he didn't conquer it. However as the Tower of London (built by William!) is not itself in the City (it's just outside it) their argument seems weak. Commented Jan 8, 2015 at 10:25

6 Answers 6


Bernard of Italy, illegitimate son of Pepin of Italy (himself a legitimate son of Charlemagne), became king of the Lombards in 810.

Edward the Martyr, briefly king of England from 975 to 978, was probably illegitimate; his father Edgar I acknowledged his younger son Æthelred as the only rightful heir (but Edgar's opinion lost most of its strength when he died).

Vladimir the Great became "Knyaz" of Kiev in 978, the title deriving from a Proto-Germanic word meaning "king". He was a natural son of Sviatoslav I, a previous ruler of the Kiev Rus'.

João I of Portugal was an illegitimate son of a previous king (Peter I) and conquered the throne after a civil war triggered by a lack of legitimate male heir.

Atahualpa was "illegitimate" son of Huayna Capac and still became Sapa Inca, roughly translated as "Emperor". The concept of illegitimacy is not the same as in contemporary Europe; the Inca had a primary wife (formally said to be his "sister"), whose children were heirs, and many secondary wives, who could be chosen for political reasons (hence not exactly "concubines" dedicated to the ruler's concupiscence). Atahualpa was son of one such secondary wife.

Paul I of Russia was most probably the son of Sergei Saltykov, and not of Peter III, husband of his mother Catherine (who became Catherine II). Paul succeeded Catherine (and was murdered 5 years later).

  • Thomas Pornin - I believe that genetic tests of the remains of Nicholas II and his family show they were related to other members of the House of Oldenburg. Thus Paul I was not only recognized by everyone in the government as of legitimate birth but seemingly actually was of legitimate birth. His mother Catherine who hated Paul and his father Peter I was probably rolling in her grave when that was announced.
    – MAGolding
    Commented May 7, 2017 at 20:15

According to the Catholics of the time, Elizabeth I was illegitimate, since the Catholic church never recognised the marriage of Henry VIII to Anne Boleyn. Not that Elizabeth was ever king ;-)

Even the Protestant parliament of England retroactively declared her illegitimate, with no place in the succession, when they annulled the same marriage (in 1536?). Naturally this inconvenience was ignored when the Tudors ran out of other heirs: Edward VI and Mary I both died, and none of Henry VIII's other "official" children survived to adulthood (including his acknowledged bastard Henry Fitzroy).

  • I was actually thinking of her when I was writing but I couldn't remember which daughter.
    – Ronan
    Commented Apr 17, 2014 at 16:13
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    Yabut, after Henry VIII severed the Church of England from the Catholic Church, his marriage was recognized by the new head of the English church, Henry VIII.
    – David H
    Commented Apr 17, 2014 at 16:25
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    @DavidH: Yabut, then he changed his mind and had it anulled. So at the time of her birth she was legitimate according to Henry, a couple of years later she wasn't, then many years later during the reign of Mary I she was again (not according to Henry, him being dead, but according to enough of the right people that she was crowned when Mary died). Being a bastard is a changeable property, it seems. Commented Apr 17, 2014 at 16:43
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    @andy256: right, that's the question. And according to the Catholic church they were not married at the time. Furthermore, according to the English parliament of 1536-ish they were not. That's what "anulling" a marriage is, as distinct from divorce. According to later English parliaments they were. The definition of a bastard involves a legal state of affairs, not a physical one. I'm not confused, just remarking as a point of interest that legal statuses are subject to retroactive change (especially for political reasons). Commented Apr 18, 2014 at 10:25
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    Perhaps as importantly, she wasn't a king. So anyone who wants to hold this answer irrelevant to the question can easily do so. I'm not too concerned about what we'd now say about her legitimacy, I suspect all but scholars of historical English law just roll their eyes at Henry's antics over the legalities of his marriages. At the time she was on the throne, she was held to be illegitimate by someone that much of Europe (but not England) considered an authority on the subject: the Pope. Commented Apr 18, 2014 at 10:36

Cleopatra's bastard with Julius Caesar, Caesarion, ruled jointly with his mother as the last kings of the Ptolemaic dynasty of Egypt.

After Caesar's assassination, Cleopatra went on to acquire a set of bastard twins from Mark Antony. Had they won their bid for power against Octavian, the male twin Alexander Helios would have been on track to succeed as the next Roman Emperor, but alas that story ended in tragedy.

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    He even ruled alone for a few days after his mother's death. Commented Apr 17, 2014 at 12:31
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    It is a little odd to impose Medieval notions of bastardy on Ptolemaic Egypt. Their rules were far different, with brother/sister marriages being preferred to keep the blood pure.
    – Oldcat
    Commented Apr 17, 2014 at 21:37
  • @Oldcat I can see that, but for the most part I'll have to take your word about Egypt since I know little. It does seem highly at odds with how the Romans did things though. I think under Roman law, if a father acknowledged a child as his then the child was legitimate under the law and none could say different.
    – David H
    Commented Apr 17, 2014 at 21:50
  • I don't think those rules applied for liaisons with foreigners. Caesar never even tried to make Caesarion is her, adopting Octavian instead.
    – Oldcat
    Commented Apr 17, 2014 at 22:12

Tancred of Lecce was King of Sicily.


Denmark and Norway had plenty. Denmark had six bastard kings in a row, five of which were fathered by Sweyn II:

  1. Harald Hen (d. 1080)
  2. Canute the Saint (d. 1086)
  3. Oluf Hunger (d. 1095)
  4. Eric Evergood (d. 1103)
  5. Niels (d. 1134)

Niels was followed by Erik Emune, bastard child of Eric Evergood. Later, his bastard son Sweyn Grathe would also take the crown. After this, there were no more bastard kings of Denmark.

The Norwegians possibly had eight bastard sons in a row (one claimed to have been such, but was not recognised), see Wikipedia.

By contrast, Sweden has had only one known bastard king, Emund the old.

  • The Norwegians didn't recognize the bastard as king, or was the king not believed to be a bastard? Why would someone insist on it?
    – CGCampbell
    Commented Jun 22, 2017 at 16:48

Manfred, Prince of Taranto, regent of Sicily 1254-1258, King of Sicily 1258-1266, was an illegitimate son of Emperor Frederick II.

Enzio, an illegitimate half brother of Manfred, married the heiress of part of Sardinia and was appointed King of Sardinia by Emperor Frederick II.

In Medieval Wales illegitimate sons who were acknowledged by their fathers had an equal right to inherit as legitimate sons. The mothers of many Welsh kings are not known and When they are known it is often not known if they were the wives or mistresses of their fathers. Nobody knows the proportion of legitimate and illegitimate sons among the Welsh kings.

And similarly there was a high proportion of illegitimate birth among the medieval Irish kings. Since there were more kingdoms in medieval Ireland than in all the reset of Europe, it is possible that most medieval European kings were bastards.

King Alfonso V (1396-1458) of Aragon etc. Left Aragon and Sicily to his legitimate brother King John II of Aragon, Sicily, etc., and his other kingdom of Sicily to his illegitimate son Ferdinand I (1423-1494)

And I have a longer list in my anser to this question:

Why couldn't bastards inherit titles?1

  • Sources would improve this answer.
    – MCW
    Commented Aug 10, 2016 at 8:26

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