Yau, 77, now a chair professor at Tsinghua University, received the Fields Medal in 1982 at the age of 33. The award, often regarded as the Nobel Prize of mathematics, made him the first Chinese mathematician to win the honor.

He is best known for his work on Calabi-Yau spaces, mathematical structures that later became central to string theory, often described as a possible "theory of everything."

"Yau really is a genius," Robert Greene, a mathematician at the University of California, Los Angeles, told the New York Times. "The quantity and quality of the math he has done is overpowering."

Shing-Tung Yau, first Chinese winner of Fields Medal. Photo courtesy of Tsinghua University

Born in Guangdong Province in 1949 and raised in Hong Kong, Yau grew up as one of eight children in a family struggling with extreme poverty. "We were very poor, at first we were almost starving," Yau said in a 2010 interview with Discover Magazine, recalling his family’s early struggles.

As a child, Yau often skipped school and spent time on the streets, but conversations with his father, a college professor, gradually drew him toward literature, philosophy and, later, mathematics. "In fact, I felt I can understand my father's conversations better after I learned geometry," he said at a talk in 2003.

His life changed sharply when his father died when Yau was 14, leaving the family in debt. Grief pushed him deeper into his studies, while financial pressure forced him to work as a tutor to help support the household.

At the Chinese University of Hong Kong, Yau quickly emerged as a gifted young mathematician. After only three years, he left without a degree to begin graduate studies at the University of California, Berkeley

In 1969, Yau arrived in the U.S. with one suitcase and less than $100 he had borrowed. At Berkeley, he received a monthly stipend of $300, sending half home to support his family. He described mathematics as "a kind of universal passport" that allowed him to explore the world and "make sense of the world," in his autobiography "The Shape of a Life" written by him and co-author Steve Nadis (2019).

On an IBM fellowship at Berkeley, "like a half-starved person showing up at an all-you-can-eat buffet", Yau took mathematical nourishment. He grew to view the subjects he studied as not strictly defined but as something "closely aligned with nature".

Under the guidance of renowned Chinese mathematician Shiing-Shen Chern, Yau progressed rapidly and completed his doctoral work at age 22. In the early 1970s, he joined leading academic institutions, including the Institute for Advanced Study in Princeton and later Stanford University, where he focused on geometry and general relativity.

Following his Fields Medal, Yau joined the University of California, San Diego, before moving to Harvard University in 1987, where he remained for more than three decades.

Shing-Tung Yau gives a lecture at Tsinghua University. Photo courtesy of Tsinghua

Returning home

In 2022, Yau retired from Harvard and returned to China to teach full-time at Tsinghua University in Beijing. "This is a major decision in his life," a colleague of Yau’s from the Chinese Academy of Sciences in Beijing told the South China Morning Post.

Although Yau had spent a lot of time teaching for free in China in recent years, the new move means "he’s ready to leave five decades of life in the U.S. behind, and devote all his time and energy to promoting the development of maths in China," said the colleague, who did not wish to be named.

Since his first return to China in 1979, Yau had regularly visited during Harvard’s summer breaks to give free lectures and help top Chinese students pursue doctoral studies in the U.S.

He also helped establish several research centers, including the Institute of Mathematical Sciences at the Chinese University of Hong Kong, the Morningside Center of Mathematics under the Chinese Academy of Sciences, and the Yau Mathematical Sciences Center at Tsinghua University.

His efforts have helped raise the global standing of Tsinghua’s mathematics department, which reportedly climbed from outside the top 100 to around 20th within a decade.

Yau now serves as dean of Qiuzhen College at Tsinghua, an institution dedicated to training young mathematics talent, and is leading a group of Chinese and international mathematicians in China’s bid to host the 2030 International Congress of Mathematicians.

His life story has been described as a powerful example of how education can transform a person’s destiny. As he wrote: "Learning is but a peep into the vast unknown, like dipping a cup into a boundless ocean."