August 8 in Military History

The English fleet under Lord Howard of Effingham and Sir Francis Drake engaged the Spanish Armada off Gravelines in the decisive battle that ended Spain's invasion attempt. English fireships had scattered the Armada the previous night, and the running battle that followed inflicted heavy damage on the Spanish fleet, which was then driven north by storms.

English fireships broke up the anchored Spanish Armada off Calais during the night, scattering the formation and setting up the Battle of Gravelines the next day. The loss of formation cohesion doomed Philip II's invasion plan and cemented English naval supremacy for the next generation.

General Robert E. Lee wrote to President Jefferson Davis offering his resignation after the devastating defeat at Gettysburg, citing the "growing failure of my bodily strength." Davis refused the resignation, and Lee continued to command the Army of Northern Virginia until Appomattox.

A combined British, Australian, Canadian, and French force launched a surprise offensive near Amiens using massed tanks, aircraft, and innovative tactics. The attack shattered German lines and advanced eight miles on the first day, the greatest single-day advance on the Western Front since 1914. Ludendorff called it "the black day of the German Army."

British, Australian, Canadian, and French forces launched a surprise combined-arms offensive at Amiens, using over 500 tanks, concentrated artillery, and tactical aviation to shatter German lines. General Erich Ludendorff called it "the black day of the German Army," and the offensive that followed led directly to the November armistice.

A Japanese cruiser force under Vice Admiral Gunichi Mikawa surprised and destroyed an Allied screening force off Savo Island near Guadalcanal, sinking four heavy cruisers and killing over 1,000 Allied sailors. It was one of the worst naval defeats in American history and left the Marines on Guadalcanal without naval protection.

The Soviet Union declared war on Japan and launched Operation August Storm, a massive invasion of Japanese-held Manchuria by 1.5 million troops. The Soviet offensive destroyed the Kwantung Army in just two weeks and was a decisive factor in Japan's decision to surrender.

Two days after the atomic bomb at Hiroshima, the Soviet Union declared war on Japan and invaded Japanese-held Manchuria the following day with 1.5 million troops and thousands of tanks. The Manchurian Strategic Offensive crushed the Kwantung Army within two weeks and shaped the political settlement of Northeast Asia.

President Richard Nixon announced in a televised address that he would resign the presidency effective the next day, becoming the only U.S. president to resign from office. The transition during the Watergate crisis raised acute concerns within the Department of Defense about civil-military command authority during the transfer of nuclear release codes.

Russian forces launched a full-scale invasion of Georgia in response to a Georgian military operation in the breakaway region of South Ossetia. The five-day war demonstrated Russia's willingness to use military force against its neighbors and foreshadowed the 2014 invasion of Crimea.