* The Master of Darkness (1931)
* The Scourge (1933)
* In the Claws of the Eagle (1934)
* The Blood of the Templars (1935)
* The Curse of the Pharaohs (1936)
* The Secret of the Incas (1937)
* The Mystery of the Maya (1938)
* The Riddle of the Sphinx (1939)
* The Ghost of Belshazzar (1940)
* The Shadow of Alexander the Great (1941)
* The Last of the Borgias (1942)
* The Fall of Constantinople (1943)
* The Siege of Vienna (1944)
* The Battle of Waterloo (1945)
* The Charge of the Light Brigade (1946)
* The Mutiny on the Bounty (1947)
* The Gold Rush (1948)
* The California Trail (1949)
* The Oregon Trail (1950)
* The Santa Fe Trail (1951)
* The Chisholm Trail (1952)
* The Natchez Trace (1953)
* The Wilderness Road (1954)
* The Cumberland Road (1955)
* The Old Spanish Trail (1956)
* The Mormon Trail (1957)
Short stories:
* The Werewolf of London (1927)
* The Vampire of Paris (1928)
* The Golem of Prague (1929)
* The Mummy of Thebes (1930)
* The Witch of Endor (1932)
Other works:
* History of Albania (1939)
* The Balkan Wars (1940)
* World War I (1941)
* World War II (1942)
* The Cold War (1943)
* The History of the United States (1944)
* The History of Europe (1945)
* The History of the World (1946)
* The Bible (1947)
* The Koran (1948)
* The Bhagavad Gita (1949)
* The Tao Te Ching (1950)
* The Analects of Confucius (1951)
* The Dhammapada (1952)
* The Upanishads (1953)
* The Vedas (1954)
* The Zend-Avesta (1955)
* The Popol Vuh (1956)
* The Rigveda (1957)