I became aware of a Cosmos Magazine article The unforgotten sisters: Sonduk, the astronomer queen by Gabriella Bernardi (hereinafter the “Cosmos Magazine article,” archived version https://archive.is/j7d1n ) from somewhat implausible claims about the ancient Korean monarch Seondeok (善德王, styled 聖祖皇姑) being discussed as fact on social media. These include claims that the female king was an astronomer herself as a princess, had a Tang ambassador called Lin Fang as a tutor, and predicted a solar eclipse as a teenager.
I found out from reading the article that it was adapted from an earlier book by the same author, Gabriella Bernardi's The Unforgotten Sisters: Astronomers and Scientists before Caroline Herschel (2016 Springer Praxis, hereinafter “Unforgotten Sisters”). On seeking out the book and reading the relevant chapter on Seondeok, I found that the chapter made similar implausible claims that I had not seen in any historical record or non-fictional discussions of historical records.
To prevent the further spread of possible misinformation and to correct the record if necessary, I set out to discover the source of these assertions about Seondeok by looking through the sources cited in the bibliography of Unforgotten Sisters. The bibliography was the only source of citations available to readers, as the Cosmos Magazine article has no citations other than Unforgotten Sisters, which in turn has no footnotes or inline citations that I could find.
Textual note: Suspicions about these claims and subsequent research were recorded contemporaneously on a Mastodon thread. This page and linked pages are a more formal documentation and expansion of the findings.
The following are the claims in the Cosmos Magazine article and/or the Seondeok chapter of Unforgotten Sisters that I found dubious for not being found in recorded history:
The problem with most of these claims are, at base, that they are not found in the known historical records from books such as the Samguk Sagi (三國史記, History of the Three Kingdoms) and Samguk Yusa (三國遺事, Stories from the Three Kingdoms). Some of the problems are elaborated in more detail below:
Seondeok's years of rule and death are in the known historical record (r. 632-647, d. 647), but her birth year is not. Yet the Cosmos Magazine article states that “She was born in 610 CE,” while the Seondeok chapter of Unforgotten Sisters makes two conflicting claims in marking her birth year correctly in the title as unknown and then, just a few lines down near the beginning of the text, claiming her birth year as 610 AD.
I could not find any source for this claim of 610 CE for the year Seondeok was born, and it seems implausible given the known historical record: For one thing, the Silla-era historical record Hwarang Segi (花郞世記) claims Seondeok's father Jinpyeong was born in 567 CE, meaning that having Seondeok in 610 CE would have made him a first-time father at the age of 43. This is not impossible, certainly, but somewhat unlikely.
Even if we disregard Jinpyeong's birth year in the Hwarang Segi, and there is some reason to do so because its authenticity as a record is in dispute, there are indications in the historical record that lead us to believe Seondeok took the throne as a mature woman in her 40s or even 50s rather than at 22:
For one, When she was elevated as her father's successor to the throne she was given the title 聖祖皇姑, which means “Imperial elder lady of the holy bloodline” with 姑 in particular connoting a female elder.
王薨, 無子, 國人立德曼, 上號聖祖皇姑. (When the king died without a son, the people of the country raised Deokman [Seondeok's name as a princess] to the throne and dedicated to her the title of Imperial Elder Lady of the Holy Bloodline.)
- 三國史記 卷第五 新羅本記第五 善德王 善德王立 (Samguk Sagi Book 5: Fifth Record of Silla, King Seondeok, King Seondeok takes the throne) Hangul translation / Scan of original record
For another, in the extremely sexist editorial commentary from the 12th century when the Samguk Sagi was put together, the king is described as an elderly woman when she started her reign:
豈可許姥嫗出閨房, 斷國家之政事乎. (How could they permit an old woman to leave the women's chambers to decide matters of state?)
- 三國史記 卷第五 新羅本記第五 善德王 論曰 (Samguk Sagi Book 5: Fifth Record of Silla, King Seondeok, In discussion) Hangul translation / Scan of original record
While, again, this commentary is very misogynistic, the sexism does not require describing a young woman as an old one: Rather, it seems likely that the king would have been berated as a callow and silly girl instead if she had taken the throne as a young woman of 22.2)
From the Cosmos Magazine article:
This sentence, found on a votive jar dedicated to her grandmother, had been written by a young girl, a Korean princess of the Silla Dynasty, when she was 15 years old.
At the age of 15 she was introduced to Confucianism, which soon became an obstacle to her thirst for knowledge.
The assertions regarding the existence of such a votive jar or the circumstances of the princess's tutelage in Confucianism are themselves suspect and are separately listed among the dubious claims. Her age during those events is another claim which also has no basis in any historical record I could find.
The Cosmos Magazine article states:
At seven, for example, a box of peony seeds arrived at the Court, from China. ... Her observation about the peonies’ lack of smell proved correct – one illustration among many of her intelligence.
The anecdote itself is well-known and attested in both the Samguk Sagi and Samguk Yusa, but no record dates this specifically to when she was seven years of age as claimed by Bernardi. Samguk Sagi states she made this prediction as a princess while her father was still king but does not pinpoint the age, while Samguk Yusa states the episode took place during her own reign when she was likely much older than seven.
The Cosmos Magazine article claims the following about the king's desire to build Cheomseongdae:
Sonduk had begged her father for several years to set out on its building, but eventually accomplished the challenge on her own.
As far as I know, however, no historical record on Cheomseongdae goes into this level of detail about the background of its construction. The first record on Cheomseongdae is the following line in Samguk Yusa:
別記云是王代鍊石築瞻星臺 (A separate record states that it was in this King[ Seondeok]'s time that stone was shaped to build Cheomseongdae.)
- 三國遺事 記異卷第一 善德王知幾三事 (Stories from the Three Kingdoms, Extraordinary Events Book 1, Three Episodes of King Seondeok's Foreknowledge) Hangul translation / Scan of original record
Later records do not go into much more detail than the year of construction, either. There is some disagreement between later records on when it was built, with the 15th-century Sejong Silok Jiriji (世宗實錄地理志, Geographical Records in the Chronicles of King Sejong) stating it to have been built in 633 CE and the 18th-century Jeungbo Munheon Bigo (增補文獻備考, Notes on Expanded and Supplemented Texts) claiming 647 CE, but both years fall within Seondeok's years of reign from 632 to 647.
The Cosmos Magazine article states:
According to the historical accounts, when astronomers were observing in Sonduk’s tower, they laid on their back and watched the celestial objects through four domes on the top, arranged in a square and oriented towards the four cardinal points.
This would be remarkable if true because there is no such historical account to my knowledge, and to the knowledge of many scholars over the centuries who have speculated on how Cheomseongdae was used for observation.3) If Bernardi can present a historical record in support of her assertion, of course, it would be a notable find. However, I personally could find no such record myself and could not trace it to any of the cited sources of Unforgotten Sisters that I could access.
The following is a record of texts I researched as possible sources of the dubious claims on Seondeok or Cheomseongdae.
This book (hereinafter “Women of Korea”) was cited in the bibliography of Unforgotten Sisters and I read the parts relevant to Seondeok as a possible source for the dubious claims made by Bernardi. However, Women of Korea does not go beyond the known historical information on Seondeok and I could not find any mention of details unique to Unforgotten Sisters such as her passion for astronomy or having a Tang ambassador as a tutor. See Passages on Seondeok from Women of Korea (1977) for the transcribed contents of this book pertaining to Seondeok.
I searched through four other references cited in the Unforgotten Sisters bibliography that might be relevant to Seondeok and that I had library access to. These were, in order of their appearance in the bibliography:
I could not find any mention of Seondeok in these books, however.
I also looked through all the working links in the Web section of the bibliography and could not find Seondeok mentioned in any of them.
Overall Unforgotten Sisters suffered from inadequate citations, having only a bibliography for the entire book without pinpoint citations, footnotes, or endnotes. The vague citations made it difficult to match ideas and information to sources. Though understandable that a work of popular science would not have the same citation standards as a full academic work, at the very least chapter-level bibliographies would have made for better attribution and sourcing.
Not directly cited in Unforgotten Sisters or the Cosmos Magazine article and found by independent search, this middle-grade novel (hereinafter “Princess of the Moon and Stars”) has many striking similarities to the assertions about Seondeok that I could not trace to any historical source. There are even passages with very similar wording.
The following is a chart of comparisons between quotes from the Cosmos Magazine article and Sŏndŏk: Princess of the Moon and Stars as seen in the Internet Archive:
| Cosmos Magazine article | Princess of the Moon and Stars |
|---|---|
| Will I ever know the truth about the stars? I’m too young to engage in theories about our Universe. I just know that I want to understand more. I want to know all I can. Why should it be forbidden? | Will we ever know the truth about the stars? I am too young to venture a theory about our universe, I only know that I want to understand more deeply. I want to know all I can know. Why should it be forbidden? (p. 77) |
| This sentence, found on a votive jar dedicated to her grandmother, had been written by a young girl, a Korean princess of the Silla Dynasty, when she was 15 years old. | [The princess, writing to her grandmother:] I have been thinking over my duties as a keeper of the Ancestor Jar, and I hope you will not grow angry with me if I slip in some of my own private thoughts. (p. 4) |
| she was very interested in astronomy in an era where no education was granted to women. | This is what I love most about studying astronomy, Grandmother. It is not just a science of planets and stars. It is a science about their marvelously complex relationships to one another. (pp. 5-6) |
| At seven, for example, a box of peony seeds arrived at the Court, from China. | “When [the princess] was but seven years old, the Emperor of China sent me a packet of peony seeds.” (p. 65) |
| her tutor, the Chinese ambassador Lin Fang, who was also an astronomer. | Word has reached me that the ambassador from China has arrived with the new official calendar. I've heard he is a great lover of astronomy and I hope to learn much from him during his stay. (pp. 4-5) Father has sent word that I may meet Lord Lin Fang (as I have learned the ambassador is called) when our court astronomers present our calendar tomorrow. (p. 11) Father has engaged Lin Fang as our tutor! (p. 50) |
| At the age of 15 she was introduced to Confucianism, which soon became an obstacle to her thirst for knowledge. | Though at thirteen, he is only one year younger than I am (p. 8) → Placing her at 14 years of age during these events |
| Sonduk, however, used to make observations every night and was mostly self-taught. | All night I measure the stars to understand their meaning for our kingdom. (p. 57) |
| Convinced of the necessity of a strictly domestic occupation for females, [Lin Fang] replied: “Surely you can’t think I can have a conversation on such important topics with a young woman! It would be unnatural and totally inappropriate.” | “I am happy to advise your father's astronomers, and you may tell them so, Lady Sŏndŏk,” Lord Lin Fang said frigidly. “But surely you cannot imagine I would converse on such a serious subject with a young lady? It would be unnatural, and wholly against the laws of propriety.” (p. 19) |
| during a solar eclipse that occurred in Korea, the young princess was able to predict the event and its duration with high accuracy | “It is mathematically impossible to have an eclipse in the tenth month of this year.” (p. 46) All week, people had been whispering that I could foretell the future because I correctly predicted that there would be no eclipse. (p. 154) |
| This angered the ambassador even more. He gave her another bit of advice: “Astronomy is not for women,” he said. “Do anything feminine, such as care of silkworms!” | When I appeared before Lin Fang for my lessons today, he dismissed me, saying, “The silkworms have need of you. Confucius would never want to stand in the way of a woman's duty to her worms.” (p. 69) |
| Eventually, this influential diplomat from a powerful neighbouring country managed to convince Sonduk’s father to preclude the princess from any further study of the stars. | “I tried to tell the Lady Sŏndŏk that astronomy is a difficult science,” Lord Lin Fang suddenly interjected, and his voice was thick and icy like the weather outside. “It should not be entrusted to a woman.” “Sŏndŏk fancies herself an astronomer,” said Father, casting an annoyed look my way. “She is a clever girl, but sometimes she oversteps her place.” (p. 47) |
| Sonduk had begged her father for several years to set out on [Cheomseongdae's] building, but eventually accomplished the challenge on her own. | It is my greatest desire to one day build an observatory here dedicated only to mapping the sky. I have hinted to Father that is what I want for my New Year's gift. (p. 9) “It is not an observatory,” he said, as I unwrapped a small red package. Inside was a lovely golden bracelet … I smiled weakly, trying to hide my disappointment … (p. 43) Every year I ask for the same thing–an observatory of my very own, and every year my Father pats my head like a child. (p. 44) |
Despite the extensive parallels between most of the dubious Seondeok/Cheomseongdae claims and Holman's novel, two such claims cannot be traced to the novel and are directly contradicted by it, either in the fictional body of the work or the historical notes in the epilogue.
At the start of Princess of the Moon and Stars, the princess is 14 years old in the 16th year of her father Jinpyeong's reign (p. 8; year of the entry on p. 6 reading “16th day of King Chinp'yŏng” in the second dateline after the day and month, but this is almost certainly a typographical error because the second lines of all other entry datelines read “16th year of King Chinp'yŏng”). This places her year of birth in the somewhat plausible second year of Jinpyeong's reign (581 CE), depending on his own birth year. 581 CE, at any rate, directly contradicts Bernardi's claimed birth year of 610 CE for the princess. As seen in the comparison chart above, however, despite the disparity in birth years the claim that events like the beginning of Lin Fang's tutelage and solar eclipse prediction took place when she was 15 years old is another close, if not exact, parallel.
Bernardi's assertion that an astronomer using Cheomseongdae laid on their back and watched the heavens through four domes is one of the few dubious claims that cannot be traced to Princess of the Moon and Stars. The fictional body of the book, which takes place during Seondeok's father Jinpyeong's reign long before the construction of Cheomseongdae, does not go into the use of the observatory, while Holman notes in the epilogue:
It is almost certain that a wooden platform made the tower even higher, but modern scientists are not absolutely sure as to how the tower was used. It is shrouded in mystery. (p. 161)
I am unsure about the strength of the wooden platform hypothesis, but at any rate this directly contradicts Bernardi's account. Furthermore, the acknowledgement of uncertainty over the specific mode of Cheomseongdae's usage is a much better-supported statement than a claim of historical records documenting a specific method, because no such record exists to the best of my knowledge.
Though not a source directly cited in Unforgotten Sisters, the Encyclopedia.com entry for Sondok makes similar claims that parallel lore from Princess of the Moon and Stars. Encyclopedia.com's own sources for this, in turn, include a now-defunct Pacific University page authored by Jennie Ngoc Vu discussing how the princess left messages in an ancestral jar for her grandmother. Other pages used as sources for the Encyclopedia.com entry, including Sondok/Sonduk's entry of the Women in World History Curriculum website and Sondok's page of the Women of Royalty website, show possible influences by Princess of the Moon and Stars in dating the peony seed anecdote to when she was seven years old and, in the Women of Royalty page, listing events very similar to those in the novel.
Judging by the access dates on the online sources, the Encyclopedia.com entry was evidently written in 2004 after the publication of Princess of the Moon and Stars and predating Unforgotten Sisters by over a decade. It seems plausible that these sources had time to percolate into scholarship as legitimate historical sources at first glance, especially where multiple sources agreed.
A survey of the supporting material for Unforgotten Sisters and the Cosmos Magazine article reveals the following support, or lack of it, for the dubious claims about Seondeok:
| Dubious claim | Any non-fiction source | Princess of the Moon and Stars |
|---|---|---|
| Grandmother's votive jar | No | Yes |
| 15 years old at the time | No | Close |
| Born in 610 CE | No | No |
| Peony anecdote at seven years of age | No | Yes |
| Lin Fang | No | Yes |
| Astronomer princess | No | Yes |
| Solar eclipse prediction | No | Close |
| Entreaty to father for observatory | No | Yes |
| Method of observation | No | No |