May 22

The First Battle of St Albans opens England's decades-long Wars of the Roses.

The First Battle of St Albans, a brief but bloody armed clash between rival noble factions loyal to the houses of York and Lancaster, opened decades of intermittent and destructive dynastic conflict in England that later became known as the Wars of the Roses.

Spanish forces massacre Aztec nobles during the festival of Tóxcatl in Tenochtitlan, a turning point in the Spanish conquest of Mexico.

Spanish conquistadors under Pedro de Alvarado, acting in Hernán Cortés's temporary absence, massacred unarmed Aztec nobles gathered for a sanctioned religious festival honoring the god Tezcatlipoca in Tenochtitlan, an unprovoked atrocity that shattered any remaining trust between the Spanish and the Aztec Empire and accelerated the conquest's violent final phase.

The Trevi Fountain is officially completed and inaugurated in Rome.

The Trevi Fountain, one of Rome's most elaborate and celebrated Baroque monuments, was officially completed and inaugurated after decades of design revisions and construction, drawing its water supply from the ancient Aqua Virgo aqueduct that had continued functioning after over two thousand years of continuous use.

The Lewis and Clark Expedition formally departs from St. Charles, Missouri, to explore the newly acquired Louisiana Territory.

The Lewis and Clark Expedition formally departed from St. Charles, Missouri, beginning its ambitious multi-year journey commissioned by President Thomas Jefferson to explore, map, and scientifically catalog the vast, newly acquired Louisiana Territory and search for a practical water route to the Pacific Ocean.

The SS Savannah departs Georgia on a voyage that makes it the first steamship to cross the Atlantic Ocean.

The SS Savannah departed the port of Savannah, Georgia, on a voyage that made it the first steam-powered vessel to successfully cross the Atlantic Ocean, though it relied primarily on conventional sail power for the vast majority of the twenty-nine day journey, using its auxiliary steam engine only sparingly.

The Wright brothers are granted a U.S. patent for their flying machine.

The Wright brothers, Orville and Wilbur, were formally granted a U.S. patent for their pioneering "Flying-Machine" design after a lengthy application process, officially recognizing the innovative three-axis wing-warping control system that had enabled their historic first successful powered, controlled flights at Kitty Hawk years earlier.

A magnitude 9.5 earthquake strikes Chile, the most powerful earthquake ever recorded.

A magnitude 9.5 earthquake struck off the coast of Chile near Valdivia, the most powerful earthquake ever instrumentally recorded anywhere in the world, triggering devastating tsunamis that caused significant destruction and loss of life not only locally but also as far away across the Pacific in Hawaii, Japan, and the Philippines.

The first Rugby World Cup kicks off in New Zealand and Australia.

The first Rugby World Cup kicked off, co-hosted jointly by New Zealand and Australia, with the host All Blacks ultimately winning the inaugural tournament on home soil, launching what became one of the most prestigious and widely watched quadrennial championships in international sport.

Ireland becomes the first country to legalize same-sex marriage through a national public referendum.

Ireland became the first country in the world to legalize same-sex marriage through a direct national popular referendum rather than legislative or judicial action, with citizens voting decisively in favor by a wide margin in a result celebrated internationally as a landmark, culturally significant moment for LGBTQ rights.

A suicide bombing at an Ariana Grande concert in Manchester, England, kills 22 people.

A suicide bomber detonated an improvised explosive device packed with shrapnel in the foyer of Manchester Arena following an Ariana Grande concert, killing 22 people, many of them children and teenagers along with their parents, in one of the deadliest terrorist attacks in recent British history.