This edited volume is written in memoriam of Professor Emeritus Ubiratan D’Ambrosio (1932 – 2021), who was a well-known Brazilian mathematics educator and historian of mathematics. This book explores the diverse facets of D’Ambrosio’s work as well as his legacy and the later adaptation of his ideas around the globe. It starts with a preface written by his son, Alexandre D' Ambrosio, who shares his personal experiences growing up with this father and his love for discovery. The book is then divided into four sections:Past and Future: Ubi’s Way of Seeing Education in the PresentRoots of EthnomathematicsEthnomathematics in ActionTrends in EthnomathematicsIt features diverse points of view and experiences that explore mathematics and culture from researchers in the Americas, Africa, Europe and South Asia. Chapters range from personal explorations of D’Ambrosio’s impact to broader views of his researchand work. This book forms part of the growing understanding of Ubiratan D’Ambrosio’s life, research, and the legacy he has left for millions of researchers, students and teachers worldwide. This book is appealing to anyone involved in mathematics education research as well as those interested in the history and future of mathematics education.