Leon Walras was a French economist born in 1834, known for his contributions to the field of general equilibrium theory. He introduced the idea that all markets in an economy are interconnected and can be analyzed together, rather than in isolation. His work laid the foundation for modern economic theory and influenced many economists. Walras is best known for his book, Éléments d'économie politique pure, published in 1874. In this work, he developed mathematical models to describe how supply and demand interact in various markets. His theories helped shape the way economists understand market dynamics and the allocation of resources.