Rear Admiral Alfred Thayer Mahan (27 September 1840 - 1 December 1914) was a United States Navy officer, naval strategist, and educator, widely considered the foremost theorist of sea power.

Born at West Point, New York to Dennis Hart Mahan (a professor at the United States Military Academy) and Mary Helena Mahan, he went to Columbia University for two years, then against his parents' wishes, transferred to the Naval Academy, where he graduated in 1859, second in his class. He was soon serving on various ships during the American Civil War.

He was appointed commander of the new United States Naval War College in 1886, where in 1887 he met and befriended a young Theodore Roosevelt who had come to lecture there. During this period Mahan organized his lectures into his most influential books, The Influence of Sea Power upon History, 1660-1783, and The Influence of Sea Power upon the French Revolution and Empire, 1793-1812, published 1890 and 1892, respectively.

The books' premise was simple, namely that in the contests between France and England in the 18th century, domination of the sea via naval power was the deciding factor in the outcome, and that control of seaborne commerce was critical to domination. Although at the beginning of the 21st century this may seem obvious, it having been demonstrated repeatedly, the notion was much more radical in Mahan's time, especially in a nation entirely obsessed with landward expansion to the west.

His books were received with great acclaim, and closely studied in Britain and Germany, influencing their buildup of forces in the years prior to World War I. Mahan himself was appointed to command the powerful new protected cruiser Chicago on a visit to Europe, where he was received and feted.

He returned to lecture at the War College for another couple of years, then retired in 1896; at which point he wrote voluminously and received honorary degrees from Harvard, Yale, Columbia, Dartmouth, and McGill.

Mahan became Rear Admiral in 1906 by an act of Congress promoting all retired captains who had served in the Civil War.

Works

• The Gulf and Inland Waters (1883)
• The Influence of Sea Power Upon History, 1660-1783 (1890) [available online from Project Gutenberg]
• The Influence of Sea Power upon the French Revolution and Empire, 1793-1812 (1892)
• Admiral Farragut (1892)
• The Interest of America in Sea Power, Present and Future (1897)
• Lessons of the War with Spain, and Other Articles (1899)
• The Problem of Asia and Its Effect Upon International Policies (1900)
• Types of Naval Officers Drawn from the History of the British Navy, with Some Account of the Conditions of Naval Warfare at the Beginning of the Eighteenth Century, and of Its Subsequent Development During the Sail Period (1901)
• Sea Power in Its Relations to the War of 1812 (1905)
• Naval Administration and Warfare: Some General Principles, with Other Essays (1908)
• Armaments and Arbitration; or, The Place of Force in the International Relations of States (1912)
• The Influence of Sea Power Upon History, 1660-1805 (abridged ed, 1980)

References

• Benjamin Apt, "Mahan's Forebears: The Debate over Maritime Strategy, 1868-1883." Naval War College Review (Summer 1997). Online. Naval War College. 24 September 2004.
• Philip A. Crowl , "Alfred Thayer Mahan: The Naval Historian" in Makers of Modern Strategy from Machiavelli to the Nuclear Age, ed. Peter Paret (Oxford: Clarendon Press, 1986)
• William E. Livezey , Mahan on Sea Power (Norman OK: University of Oklahoma Press, 1981)
• W. D. Puleston , Mahan: The Life and Work of Captain Alfred Thayer Mahan (New Haven: Yale University Press, 1939)
• Robert Seager , Alfred Thayer Mahan: The Man and His Letters (Annapolis, MD: Naval Institute Press , 1977)