Karl Schwarzschild was a German physicist and astronomer, best known for his work in the field of general relativity. Born in 1873, he made significant contributions to theoretical physics, particularly in understanding the behavior of black holes. His most famous solution, the Schwarzschild solution, describes the gravitational field outside a spherical mass, laying the groundwork for modern astrophysics. In addition to his work on black holes, Schwarzschild also studied stellar structure and cosmology. He served in the German army during World War I, where he continued his research despite facing challenging conditions. Tragically, he died in 1916 from an illness, but his legacy endures in the field of physics.