Theodor Mommsen was a German classical scholar, historian, and writer. He is best known for his work "The History of Rome," a multi-volume history of ancient Rome that earned him the Nobel Prize in Literature in 1902. Mommsen's scholarship and research significantly influenced the study of Roman history and law. He was also involved in politics and was a prominent figure in the German liberal movement. Mommsen's contributions to the understanding of ancient Rome and his literary achievements have solidified his legacy as one of the most influential historians of his time.