Heisuke Hironaka, a towering figure in the world of mathematics and a recipient of the prestigious Fields Medal, passed away on March 18, 2026, in Tokyo, Japan, at the age of 94. His groundbreaking work in algebraic geometry, particularly his resolution of singularities, profoundly impacted the field and earned him international acclaim. Hironaka's intellectual journey spanned decades, leaving an indelible mark on both research and education across continents.

Born on April 9, 1931, in Yamaguchi Prefecture, Japan, Heisuke Hironaka displayed an early aptitude for mathematics. He pursued his higher education at Kyoto University, where he earned his Bachelor of Science in 1954 and his Master of Science in 1956. His foundational studies in Japan laid the groundwork for his future pioneering contributions to complex mathematical problems.

Hironaka then ventured to the United States, continuing his studies at Harvard University. Under the mentorship of the renowned Oscar Zariski, he completed his Ph.D. in 1960, focusing on the theory of birational blowing-up. This period marked a crucial phase in his development as a mathematician, as he delved into the intricacies of algebraic varieties.

His academic career saw him hold esteemed positions at several prominent institutions. He served as an Associate Professor at Brandeis University from 1960 to 1963, followed by a professorship at Columbia University from 1964 to 1968. In 1968, he joined Harvard University as a professor of mathematics, a role he held until becoming emeritus in 1992, shaping generations of mathematicians.

The pinnacle of Heisuke Hironaka's career arrived in 1970 when he was awarded the Fields Medal at the International Congress of Mathematicians in Nice, France. This honor, often regarded as the Nobel Prize of mathematics, recognized his monumental achievement in proving the resolution of singularities of an algebraic variety over a field of characteristic zero. His proof provided a fundamental tool for understanding the structure of algebraic varieties.

Beyond his research, Hironaka was a dedicated educator and advocate for mathematical sciences. He returned to Japan for a joint professorship at the Research Institute for Mathematical Sciences at Kyoto University from 1975 to 1983, serving as its director from 1983 to 1985. He also took on leadership roles, including serving as president of Yamaguchi University from 1996 to 2002.

Committed to nurturing young talent, Heisuke Hironaka established the Japan Association for Mathematical Sciences (JAMS) in 1984. Through this organization, he directed summer seminars for high school and college students for over two decades, fostering a love for mathematics and providing fellowships for Japanese students to pursue doctoral studies abroad. He was also involved in the creation of the Sansu Olympics, a math competition for children.

His contributions were further recognized with numerous accolades, including the Asahi Prize in 1967, the Japan Academy Prize in 1970, and the Order of Culture from Japan in 1975. In 2004, he was honored with the Legion of Honour. Heisuke Hironaka's legacy endures not only through his profound mathematical theorems but also through the countless students and colleagues he inspired and the institutions he helped to build.

Heisuke Hironaka's life was a testament to intellectual curiosity, perseverance, and a deep commitment to advancing human knowledge. His passing marks the end of an era for algebraic geometry, but his work will continue to illuminate pathways for future generations of mathematicians.