In the grand tapestry of mathematical genius, Leonhard Euler's thread shines uniquely bright, weaving a legacy that spans the breadth of pure and applied mathematics. Ronald S. Calinger's meticulously researched biography, "Leonhard Euler," presents the first full-scale exploration of a man whose intellectual feats rival those of Archimedes, Newton, and Gauss. Through a narrative enriched by Euler's extensive published works and correspondences, Calinger not only charts the monumental life of this 18th-century luminary but also contextualizes his work within the vibrant tapestry of his times—capturing the personal, intellectual, and social currents that shaped his extraordinary contributions. From his early days in Basel to his defining periods in St. Petersburg and Berlin, Euler's life was a testament to ceaseless innovation. His foundational work in fields as diverse as calculus, number theory, optics, and fluid mechanics, alongside significant advancements in areas like shipbuilding and music theory, underscored a mind of unparalleled analytical power. Even as personal challenges, including near-total blindness, sought to dim his brilliance, Euler's prodigious output—culminating in works that brought pan-European prestige to the academies of Petersburg and Berlin—remained undiminished. Calinger's biography is more than a recounting of Euler's achievements; it is a vivid portrayal of a man whose work laid the groundwork for modern mathematics and demonstrated the profound influence of mathematics on the Enlightenment. Through "Leonhard Euler," readers are invited to witness the life and legacy of a true polymath who shaped the contours of intellectual history.