September 10 in Military History

An English army under Edward Seymour, Duke of Somerset, crushed a Scottish force under the Earl of Arran at Pinkie Cleugh east of Edinburgh in one of the decisive battles of the Rough Wooing. English arquebusiers, cavalry, and naval gunfire from warships offshore broke the Scottish pike formations and produced roughly 6,000 Scottish dead. The battle is often called the first modern battle on British soil.

Master Commandant Oliver Hazard Perry's American squadron defeated Captain Barclay's British squadron at the Battle of Lake Erie, capturing the entire enemy fleet, the first time a complete British naval squadron had been taken.

The Peruvian Congress granted Simón Bolívar supreme military and political authority to defeat the remaining Spanish royalist forces in South America. Bolívar used this power to organize the campaign that culminated in the Battle of Ayacucho on December 9, 1824, the decisive engagement that ended Spanish colonial rule in South America.

General Zachary Taylor's Army of Occupation advanced toward the fortified Mexican city of Monterrey during the Mexican-American War. The upcoming battle (September 21-24) would showcase Taylor's tactical aggressiveness and the effectiveness of American artillery, but the hard-won victory would be controversial when Taylor granted the Mexican garrison an eight-week armistice.

Austria signed the Treaty of Saint-Germain-en-Laye with the Allied and Associated Powers, formally dissolving the Austro-Hungarian Empire and establishing the Republic of Austria. The treaty stripped Austria of its military capacity, limiting its army to 30,000 men, and prohibited union with Germany, a provision that Hitler would violate with the Anschluss in 1938.

Canada declared war on Nazi Germany, becoming the first Commonwealth nation to make an independent declaration of war. The one-week delay after Britain's declaration was deliberate, emphasizing Canadian sovereignty. Canada would mobilize over one million men and women during the war, a remarkable contribution from a nation of eleven million people.

German forces occupied Rome following the Italian armistice announcement, despite Italian army units attempting to defend the capital. The fighting at Porta San Paolo cost over 400 Italian military and civilian lives. King Victor Emmanuel III and Marshal Badoglio had already fled to Brindisi, leaving Rome's defenders without leadership or orders.

Iva Toguri D'Aquino, an American citizen of Japanese descent who had broadcast for Radio Tokyo during the war under the on-air name Orphan Ann, was arrested by US Army Counterintelligence Corps agents in Yokohama. She became the public face of Tokyo Rose, the composite figure blamed for propaganda broadcasts to US troops in the Pacific. She was convicted of treason in 1949 and pardoned by President Ford in 1977.

The Royal Navy concentrated cruisers HMS Mauritius and HMS Euryalus plus eight destroyers in the Persian Gulf as the Abadan Crisis escalated with Iran. Prime Minister Mohammad Mosaddegh had nationalized the Anglo-Iranian Oil Company in May, and Britain responded with blockade, military buildup, and covert operations. The crisis culminated in the 1953 CIA-MI6 coup that overthrew Mosaddegh.

Hungarian Foreign Minister Gyula Horn announced that Hungary would no longer enforce its border with Austria against East German citizens seeking to emigrate to the West. Over the following three days roughly 13,000 East Germans who had been waiting in Hungary crossed to Austria. The breach of the Iron Curtain was a decisive step in the collapse of the East German state and the broader unraveling of Soviet power in Europe.