Standard portrait of Queen Seondeok enshrined in Sungmojeon Hall of Buinsa Temple, Daegu (via Namu Wiki)

 

Life

Queen Seondeok was born in 610 CE as Princess Deokman, daughter of King Jinpyeon of the Silla Kingdom, one of the fighting states of Korea at the time, and the one that eventually unified the peninsula. ¹

She was known for her intelligence, especially in her observation of nature from a young age. This influenced her father, who had no sons, to make her heir to the throne instead of his son-in-law. She became Queen Seondeok in 632 or 634, and remained in power until her death in 647. ²

A famous story about the young Princess Deokman involved the visit of the Chinese astronomer and ambassador who came to Silla to negotiate adoption of the Chinese calendar with King Jinpyeong (Silla was then the strategic ally of the Tang dynasty). ³ Deokman tried, without success, to engage the man in discussion about astronomy, and when she demonstrated her ability to predict the duration and progression of an eclipse, he told her, “Astronomy is not for women!” Supposedly, her father even followed the ambassador’s advice to prevent his daughter from learning more astronomy, but this did not stop Queen Seondeok’s contributions to astronomy when she rose to the throne. ⁴

Notably, she ordered the construction of Cheomseongdae (첨성대; 瞻星臺) in Gyeongju, what was possibly the first observatory in East Asia. The construction reportedly occurred between 633 and 647. ⁵ It was said to have served the purpose of helping farmers better plan their harvest cycles. ⁶

Seondeok was also known for reinforcing Silla’s ties with the Tang dynasty and further encouraging Buddhism – the official state religion, with the monarch viewed as the reincarnation of Buddha – by constructing the Hwangnyongsa temple. ⁷

 

Work in Astronomy

The Cheomseongdae consisted of 365 stones – representing the number of days in a year – with a base of 12 stones – the number of months in a year. ⁸ Ancient Korean astronomers like Seondeok observed the positions and movements of celestial bodies and used the data to create calendars and predict solstices and eclipses. As a monarch, Seondeok’s knowledge of astronomy was even more important as it was part of her role of serving and communicating between the heavens and her people, including predicting future events and “leading [her] people on the right track” in light of them – the Royal Palace had a special astronomy bureau for this reason. ⁹ 

Built in the era before telescopes, Seondeok’s Cheomseongdae had an observation deck at the top where observers can lie down and four domes – which are also placed as cardinal points of a compass – to look through at specific areas of the sky. ¹⁰ The tower – which is 9 metres tall – also had a South-facing window that allowed the sun’s rays to pass through and hit the interior floor during equinox, making the tower function additionally as a sundial. ¹¹

In the 3 centuries after the construction of the Cheomseongdae until the fall of Silla, records of astronomical observations more than doubled compared to the kingdom’s previous 7 centuries. ¹²

 

Experience and legacy as an Ancient Korean woman astronomer

Queen Seondeok was a mostly self-taught astronomer, though she did receive some education from royal astronomers before her father halted her education in astronomy at the advice of the Chinese ambassador. ¹³

Women had relatively high status in Silla, where traditions based on Buddhism and Shamanism – native Korean religion where traditionally female shamans (무당; Мudang) facilitated communication between humans and gods (a ritual called 긋; Gut)  – prioritised religion and bloodline over gender. As people who continued the family line, women were given freedom of movement, right to pass down their family name, the right to remarry, inherit, pay taxes and become head of the household. Women from the aristocracy participated in judicial and political activities. Due to a lack of male heirs in the direct bloodline, Seondeok’s successor was also a woman – Queen Jindeok. ¹⁴

However, women’s freedoms deteriorated over the course of the Goryeo period after the fall of Silla, as well as later periods. Shamanism also became stigmatised in modern times and women who are shamans live in the margins of society. ¹⁵

Before a study in 2001 confirmed it, historians also debated whether the Cheomseongdae was built for the purpose of astronomy, despite the fact that its name means “star-gazing tower”. ¹⁶ Some historians also make unsupported claims that the tower was used as a temple for the worship of Seondeok because the shape of it seems to reprepresent “the feminine form”. ¹⁷

Bibliography

Bernardi, Gabriella. 2016. “Sonduk (?–647).” In The Unforgotten Sisters: Female Astronomers and Scientists before Caroline Herschel, by Gabriella Bernardi, 1st ed. Springer Science+Business Media. https://search.credoreference.com/articles/Qm9va0FydGljbGU6NDQ2MDI4MQ==?aid=99238.

Cartwright, Mark. “Queen Seondeok.” World History Encyclopedia. Accessed July 10, 2024. https://www.worldhistory.org/Queen_Seondeok/#google_vignette.

DeBakcsy, Dale. A History of Women in Astronomy and Space Exploration: Exploring the Trailblazers of STEM. Pen and Sword History, 2023.

“Shamanism in Korea 상세보기| Citizen JournalistsEmbassy of the Republic of Korea to Norway.” 외교부. Accessed July 10, 2024. https://overseas.mofa.go.kr/no-en/brd/m_21237/view.do?seq=141&srchFr=&srchTo=&am#:~:text=Shamans%2C%20called%20Mudang(%EB%AC%B4%EB%8B%B9),one%20and%20comes%20with%20stigma.