April 7

Byzantine Emperor Justinian I issues the first part of the Corpus Juris Civilis, a landmark codification of Roman law.

Byzantine Emperor Justinian I promulgated the first installment of the Corpus Juris Civilis, a sweeping codification and reorganization of centuries of often contradictory Roman law into a single coherent legal system. The compilation, developed under the direction of jurist Tribonian, became enormously influential, forming the basis for civil law systems still used across much of continental Europe and beyond today.

Holy Roman Emperor Charles IV founds Charles University in Prague, the oldest university in Central Europe.

Holy Roman Emperor Charles IV issued a charter founding Charles University in Prague, establishing what remains the oldest university in Central Europe. The university quickly became a major center of medieval learning, attracting students and scholars from across the region and later playing an important role in the religious reform movements associated with Czech theologian Jan Hus.

Ferdinand Magellan's expedition arrives at Cebu in the Philippines during its circumnavigation of the globe.

Ferdinand Magellan's expedition, continuing its attempt to circumnavigate the globe after his death would later occur mid-voyage, arrived at Cebu in the Philippines, where Magellan formed an alliance with a local ruler and introduced Christianity to the islands. His subsequent death weeks later in a conflict with a rival local chieftain marked one of the most dramatic episodes of the historic voyage.

Ludwig van Beethoven premieres his Third Symphony, the "Eroica," in Vienna.

Ludwig van Beethoven premiered his Third Symphony, the "Eroica," in Vienna, a work whose unprecedented length, emotional intensity, and structural innovation is widely regarded by music historians as a turning point marking the beginning of the Romantic era in classical music. Beethoven had originally intended to dedicate the symphony to Napoleon before angrily withdrawing the dedication after Napoleon crowned himself emperor.

Mount Vesuvius erupts violently, devastating Naples and the surrounding region of southern Italy.

Mount Vesuvius erupted violently for the first time in nearly two decades, sending lava flows and ash clouds over Naples and surrounding towns, destroying homes and killing over 100 people. The eruption, one of the volcano's most destructive of the modern era, prompted major evacuations and renewed scientific study of the volcano that had famously destroyed Pompeii nearly 1,800 years earlier.

The World Health Organization is established as a specialized agency of the United Nations.

The World Health Organization was formally established as a specialized health agency of the newly formed United Nations, tasked with coordinating international public health efforts, combating infectious diseases, and setting global health standards. The date of its founding is now commemorated annually as World Health Day, and the organization has since played a central role in campaigns against diseases like smallpox and polio.

The first Request for Comments document, RFC 1, is published, marking a symbolic starting point for what became the internet.

Computer scientist Steve Crocker published RFC 1, the first in what became an enormous ongoing series of technical documents used to develop and standardize the protocols underlying the ARPANET, the U.S. government-funded precursor to the modern internet. The Request for Comments system's collaborative, openly published approach to technical standard-setting became a defining feature of internet governance.

U.S. forces capture Baghdad as Saddam Hussein's government collapses during the Iraq War.

American forces advanced into central Baghdad as the Iraqi government's control collapsed, a symbolic turning point in the initial invasion phase of the Iraq War that had begun weeks earlier. Iraqi President Saddam Hussein went into hiding and was not captured until December of that year, though the war's subsequent insurgency and occupation phase would continue for years afterward.

A truck attack on a pedestrian street in Stockholm, Sweden, kills five people.

A hijacked truck plowed into pedestrians on a busy shopping street in central Stockholm, Sweden, killing five people and injuring more than a dozen others in an attack later claimed to have been inspired by the Islamic State. The attack was one of several vehicle-ramming incidents that struck European cities during the mid-2010s, prompting increased security measures in pedestrian areas.

Ketanji Brown Jackson is confirmed as the first Black woman to serve on the U.S. Supreme Court.

The U.S. Senate confirmed Ketanji Brown Jackson to the Supreme Court, making her the first Black woman ever to serve on the nation's highest court after more than two centuries of the institution's existence. Jackson, a former federal public defender and appellate judge, was nominated by President Joe Biden to fill the seat of retiring Justice Stephen Breyer.