Queen Seondeok was the first female ruler of the ancient Korean kingdom of Silla, reigning from 632 to 647 AD. She is known for her intelligence, political acumen, and efforts to promote Buddhism, which played a significant role in unifying the kingdom. During her reign, Queen Seondeok oversaw various cultural and scientific advancements, including the construction of the Cheomseongdae observatory, one of the oldest astronomical observatories in East Asia. Her leadership helped strengthen Silla's position among the Three Kingdoms of Korea, which included Goguryeo and Baekje.