August 20 in History

Khalid ibn al-Walid, whom Muhammad had nicknamed "The Sword of God," led Arab Muslim forces against a Byzantine army at the Battle of Yarmouk on August 20, 636. The engagement lasted six days on a plain between the Yarmouk River and its tributaries. Khalid exploited sandstorms, cavalry feints, and the Romans' inability to retreat across the ravine behind them. When the Byzantine line broke, thousands of soldiers fell into the gorge. The defeat permanently ended Byzantine control over Syria, Palestine, and eventually Egypt. The conquest brought Arabic language, Islamic religion, and new administrative systems to a region that had been under Greco-Roman influence for nearly a thousand years.

Ramon Mercader, a Spanish communist operating under Soviet intelligence orders, gained Leon Trotsky's trust by dating one of his secretaries and visiting his fortified compound in Mexico City repeatedly. On August 20, 1940, Mercader struck Trotsky in the head with an ice axe while the exiled revolutionary was reading a manuscript. Trotsky fought back, biting Mercader's hand, and bodyguards subdued the assassin. Trotsky died the following day at age 60. Stalin had been hunting Trotsky for over a decade, seeing him as the only credible alternative to Stalinist communism. Mercader served twenty years in a Mexican prison, never revealing his identity, and was later awarded the Hero of the Soviet Union medal.

Soviet tanks rolled into Prague at midnight on August 20, 1968, ending eight months of political liberalization known as the Prague Spring. Alexander Dubcek had been trying to create "socialism with a human face," loosening censorship, allowing political pluralism, and decentralizing the economy. Moscow saw this as an existential threat. Roughly 200,000 Warsaw Pact troops from the Soviet Union, Poland, Hungary, and Bulgaria occupied the country within hours. Czechoslovak citizens resisted nonviolently: they removed street signs to confuse invaders, surrounded tanks to argue with crews, and ran clandestine radio stations. Seventy-two Czechoslovaks were killed. Dubcek was arrested, flown to Moscow, and forced to sign a capitulation. Soviet troops remained until 1991.

Radio station 8MK in Detroit (later known as WWJ) broadcast election returns on August 20, 1920, making it one of the first commercial radio stations in the United States. The station was operated by the Detroit News and initially served as a promotional tool for the newspaper. KDKA in Pittsburgh, which broadcast the presidential election returns on November 2, 1920, is more commonly cited as the first commercial station, though the distinction depends on how you define "commercial." Regardless of priority, both stations demonstrated that radio could deliver news and entertainment directly into homes in real time, bypassing the newspaper's next-morning delivery cycle and fundamentally changing how Americans consumed information.

Pope Sylvester II sent a crown to Stephen I of Hungary, who was crowned on Christmas Day in the year 1000 (or possibly January 1, 1001), transforming a confederation of Magyar tribes into a recognized Christian kingdom. Stephen had defeated his pagan rival Koppany and married Gisela of Bavaria, aligning Hungary with Western Christianity rather than the Orthodox tradition of Byzantium. He established ten dioceses, imposed tithes, banned pagan practices, and created a system of royal counties that centralized power. The Holy Crown of Hungary that he received (or a version of it) became the most sacred symbol of Hungarian statehood and is still displayed in the Hungarian Parliament building today.

Voyager 2 launched on August 20, 1977, sixteen days before Voyager 1, but its trajectory was slower. Its sister craft passed it and took the name that implied it went first. Voyager 2 had a different mission: visit all four outer planets. It flew past Jupiter, Saturn, Uranus, and Neptune — the only spacecraft ever to visit the last two. At Neptune in 1989, it photographed Triton's geysers and a Great Dark Spot that later disappeared. As of the 2020s, it's in interstellar space, still transmitting. Still moving away from us at 55,000 kilometers per hour.