Gottlob Frege was a German mathematician, logician, and philosopher who made groundbreaking contributions to logic and the philosophy of language in the late 19th and early 20th centuries. He is considered one of the founders of modern logic and analytic philosophy, developing a formal system of quantified predicate logic that revolutionized the field. Frege's work laid the foundations for modern mathematical logic and had a profound influence on subsequent developments in logic, mathematics, and philosophy of language.