HISTORY 982 NOTICES OF THE AMERICAN MATHEMATICAL SOCIETY VOLUME 69, NUMBER 6 was a big event in the department (Stanford Statistics), not just for me.” And Donald Rubin, Harvard University, writes in [1] that “Despite his dominant reputation, Rao always seemed to be extremely modest and, moreover, helpful to younger colleagues.” Efron further writes in [1] that “the 25-year-old Rao in 1945 [2] introduced differential geometry into statistical inference, opening up the burgeoning field now called information geometry.” Rao distances combined with con- formal mappings are seen in modern applications such as virtual tourism [4,5]. Shun-ichi Amari, Tokyo University, writes in [1] that “[C. R.] Rao’s initiation of information geometry is one of the many achievements for which he was awarded the US National Medal of Science. Information geometry has grown to become an important tool not only in statistics but also in artificial intelligence, data science, signal processing, physics, and many other fields since it elucidates the fundamental structure of the manifold of probabilities.” This tribute to Professor C. R. Rao in the Notices is to celebrate his 101st birthday, and it can be treated as a se- quel to the two tributes to him by two groups of renowned statisticians and mathematicians published during the centenary. See B. Efron et al. [1] and Prakasa Rao et al. [3]. Introduction Professor C. R. Rao (Calyampudi Radhakrishna Rao) is a well-known name in statistics, probability, mathematics, information geometry, econometrics, and related fields. He currently lives in Buffalo, New York, and actively partici- pated in an event to mark his 101st birthday that was held online in October 2021 with his former students, long-time friends, and collaborators. His special awards include the US National Medal of Science, the Indian Government’s Padma Vibhushan, and the Guy Medal in Gold from the Royal Statistical Society, London. His most recent award is the 2022 IEEE Honorary Membership, which is selected by the Board of Directors of IEEE from among outstand- ing individuals who have rendered meritorious service to humanity. C. R. Rao’s famous results include the Rao– Blackwell Theorem, Fisher–Rao Information, Rao distance, Kagan–Linnik–Rao Theorem, and Cramér–Rao bounds. At the age of 25, he published major results from India before traveling to Cambridge to pursue a PhD under R. A. Fisher. See Table 1 for more detailed highlights of his career. Another National Medal of Science awardee, Bradley Efron of Stanford University, wrote during C. R. Rao’s centenary [1] that “When the fat second edition of Rao’s magisterial book on linear statistical inference arrived on my desk (when I was a first-year postdoctoral student), it C. R. Rao (1920–) Celebrates His 101st Birthday George E. Andrews, G. J. Babu, Zhidong Bai, David Banks, Herman Chernoff, Roy Frieden, Yasunori Fujikoshi, Kanti V. Mardia, Basilio de Bragança Pereira, Urmila Pingle, M. B. Rao, Arni S. R. Srinivasa Rao, James Rosenberger, S. R. S. Varadhan, and Yuehua Wu Communicated by Notices Associate Editor Scott Sheffield. For permission to reprint this article, please contact: reprint-permission @ams.org. DOI: https://dx.doi.org/10.1090/noti2492