Librarian of the Bibliotheca Hertziana. Schudt studied art history in Frankfurt, Munich and Berlin. He joined the Hertziana after graduation in 1920 and remained there his entire career. Schudt edited a critical edition of Giulio Mancini's Viaggio per Roma in 1923. Schudt became a trustee of the Palazzo Zuccari library shortly thereafter. In 1930, Schudt issued his Guide di Roma, an analysis of Roman guidebooks from the Mirabilia to the nineteenth century. Schudt understood that the genesis of Roman travel literature demonstrated the reasons for writing them. His book traced the genre and standardized what was known of Rome through the centuries. Schudt's next work took him twenty years. He read nearly every diary and memoir of a traveler to Rome during the Baroque era. He remained loyal to his country, if not Hitler, during the Second World War (Wittkower), publishing a small book on Caravaggio in 1942. Well after the war, Schudt published his long-term research in travel history as Italienreisen im 17. und 18. Jahrhundert (Travels to Italy of the 17th and 18th Centuries) in 1959. All the while, Schudt worked at the librarian of the Hertziana, building the collection into the single most important research library for Roman studies. A festschrift dedicated to Schudt, Franziskus Wolff Metternich and in memory of Leo Bruhns, who died while editing the volume, was produced in 1961.
edited, Mancini, Giulio. Giulio Mancini: Viaggio per Roma. Leipzig Klinkhardt & Biermann 1923; Le guide di Roma: materialien zu einer geschichte der römischen topographie. Vienna: B. Filser, 1930; Italienreisen im 17. und 18. Jahrhundert. Vienna: Schroll, 1959
[obituary:] Wittkower, Rudolf. "Ludwig Schudt." Burlington Magazine 104 no. 706 (January 1962): 35; "In memoriam Ludwig Schudt." Römisches Jahrbuch für Kunstgeschichte 9/10 (1961/62).