The Synod of Frankfurt, convened under Charlemagne's authority, brought together clergy from the Frankish kingdom, Italy, and England to reject the Byzantine Second Council of Nicaea's stance on icon veneration and to condemn Adoptionism, a Spanish theological movement. The gathering demonstrated Charlemagne's growing role as arbiter of Western Christian doctrine, years before his imperial coronation in Rome.

Gandhi and about 78 companions departed Sabarmati Ashram bound for the coastal village of Dandi, launching a 24-day march that became the most visible act of civil disobedience in India's independence struggle. The tax on salt, a substance every Indian needed, symbolized colonial control over daily life, and Gandhi's simple act of making it himself electrified a nation.

Days after Stalin's death, the Soviet Union staged an elaborate funeral procession through Moscow. Enormous crowds, many drawn less by devotion than by fear and curiosity after three decades of Stalin's rule, pressed into the city center, and the resulting stampede killed an estimated 100 to 500 people, a toll the state suppressed for years.

Working at CERN, the European particle physics laboratory, Tim Berners-Lee circulated a proposal to his supervisor outlining a system of linked hypertext documents to help researchers share information across incompatible computers. His supervisor, Mike Sendall, famously scrawled "vague but exciting" on the cover. Within three years, Berners-Lee's idea had grown into the World Wide Web.

At a ceremony in Independence, Missouri, the foreign ministers of Poland, Hungary, and the Czech Republic deposited their instruments of accession, formally making their countries NATO members. The move extended the alliance eastward for the first time since the Cold War's end, reshaping Europe's security architecture a decade after the Iron Curtain fell.

Adam Powell and Donna Williams released Neopets from a university dorm, letting users adopt and care for cartoon creatures using a fictional currency earned through simple games. The site grew into a cultural touchstone for millennial internet users and pioneered advertising and virtual economy models that shaped later social games and platforms.

In a ceremony in Independence, Missouri, the foreign ministers of the Czech Republic, Hungary, and Poland deposited their instruments of accession, formally entering NATO a decade after the fall of communism in Eastern Europe. The expansion marked a historic reversal, bringing former Soviet satellite states into the alliance built to counter the USSR, and set a precedent for further eastward enlargement that Russia bitterly opposed.

NASA released striking Chandra X-ray Observatory imagery showing the Crab Nebula's central pulsar, the collapsed core of a star that exploded in 1054 AD, spinning 30 times per second and blasting out particle jets visible across the electromagnetic spectrum. The image became one of the most widely reproduced astronomical photographs, illustrating stellar death and its violent afterlife.