They called it one of the most powerful tools in mathematics—a way to represent complex functions as an infinite sum of simpler terms. It was developed by an English mathematician named Brooke Taylor. Born in 1685, Taylor studied at Cambridge, earning a law degree, but devoted himself to pure mathematics. By his twenties, he had contributed to geometry, mechanics, and the mathematics of vibrating strings, helping lay the foundations of wave theory. In 1715, he introduced what we now call the Taylor series, an expansion that expresses a function as the sum of its derivatives at a single point, with each term multiplied by powers of the input offset. This allowed mathematicians to approximate functions with polynomials, making them easier to analyze, compute, and apply. The Taylor series became indispensable in physics, engineering, and mathematical analysis—from orbital mechanics and optics to thermodynamics, quantum theory, and numerical algorithms. Brook Taylor died in 1731 at just 46, but his method remains a cornerstone of mathematical analysis, shaping how we model the world.