Leonhard is a name that can refer to several notable figures, including the mathematician Leonhard Euler, who made significant contributions to various fields such as calculus, graph theory, and mechanics. Born in 1707 in Switzerland, Euler is often regarded as one of the greatest mathematicians of all time, with many mathematical concepts named after him. In addition to Euler, the name Leonhard is also associated with Saint Leonard, a Christian saint known for his work in the 6th century. He is often invoked for his intercession in matters related to childbirth and is the patron saint of prisoners and captives.