How was Theodor Mommsen awarded the Noble Prize in Literature?

Name: Theodor Mommsen.
Real Name: Christian Matthias Theodor Mommsen.
Date of Birth: November 30 , 1817.
Birth Place: Garding, Duchy of Schleswig, Denmark.
Died: November 1, 1903.
Death Place: Charlottenburg, Brandenburg, Kingdom of Prussia, German Empire.
Nationality: German.
Education: Gymnasium Christianeum University of Kiel.
Subjects Of Study: Roman Empire, ancient Rome, Roman law, constitutional law, epigraphy.
Popularly Known: The greatest classical historian of the nineteenth century.
Noble Prize Year: Nobel Prize for Peace in 1902, for the greatest living master of the art of historical writing, with special reference to his monumental work, A history of Rome.