May 23

Seljuk Turks defeat the Ghaznavids at the Battle of Dandanaqan, establishing Seljuk power across a vast region of Central Asia.

Seljuk Turkish forces decisively defeated the rival Ghaznavid Empire at the Battle of Dandanaqan in present-day Turkmenistan, a victory that established Seljuk dominance across a vast swath of Central Asia and Persia and set the stage for their later dramatic expansion westward into Anatolia and the broader Middle East.

Joan of Arc is captured by Burgundian forces at the Siege of Compiègne, later leading to her trial and execution.

Joan of Arc was captured by Burgundian forces allied with the English during a sortie outside the besieged city of Compiègne, when the drawbridge was reportedly raised before she could retreat inside, beginning the chain of custody transfers and legal proceedings that led to her trial for heresy and execution less than a year later.

Religious reformer Girolamo Savonarola is executed by burning in Florence, Italy.

Religious reformer Girolamo Savonarola, whose fiery apocalyptic preaching had briefly dominated Florentine politics and inspired the famous "Bonfire of the Vanities," was hanged and then burned in the city's main square after being condemned for heresy and defying papal authority following his excommunication.

An English church court declares King Henry VIII's marriage to Catherine of Aragon null and void, clearing the way for his marriage to Anne Boleyn.

An English ecclesiastical court presided over by Archbishop Thomas Cranmer declared King Henry VIII's twenty-four-year marriage to Catherine of Aragon null and void, a ruling that cleared the legal path for his subsequent marriage to the already-pregnant Anne Boleyn and further deepened his rupture with the Roman Catholic Church.

The Duke of Marlborough leads Allied forces to a decisive victory over France at the Battle of Ramillies.

The Duke of Marlborough led a combined Allied army to a decisive victory over French forces at the Battle of Ramillies during the War of the Spanish Succession, dramatically shifting military momentum in the conflict and enabling the rapid Allied conquest of most of the Spanish Netherlands within weeks.

South Carolina ratifies the U.S. Constitution, becoming the eighth state to join the Union.

South Carolina ratified the newly drafted United States Constitution by a comfortable margin, becoming the eighth state to join the Union under the new stronger federal framework designed to replace the weaker, largely unworkable Articles of Confederation that had governed the young nation since independence.

Canada establishes the North-West Mounted Police, the forerunner of the Royal Canadian Mounted Police.

The Canadian federal government established the North-West Mounted Police, a paramilitary force created to maintain law and order and assert Canadian federal authority in the country's vast, sparsely settled western territories, later evolving into the modern Royal Canadian Mounted Police, an enduring symbol of Canadian national identity.

Italy enters World War I on the side of the Allied powers.

Italy formally declared war on Austria-Hungary and entered World War I on the side of the Allied powers, having previously been aligned with the opposing Central Powers before negotiating secret territorial promises from Britain and France in exchange for abandoning its earlier alliance commitments.

SS leader Heinrich Himmler dies by suicide while in British custody.

SS leader Heinrich Himmler, one of the chief architects of the Holocaust and head of the Nazi security apparatus, took his own life by swallowing a hidden cyanide capsule shortly after being captured and identified by British forces attempting to interrogate him at the end of World War II.

Voters in Northern Ireland approve the Good Friday Agreement in a referendum, with roughly 75 percent in favor.

Voters in Northern Ireland overwhelmingly approved the Good Friday Agreement in a public referendum, with roughly 75 percent voting in favor, formally endorsing the historic power-sharing governmental framework negotiated among the region's political parties that helped bring an end to nearly three decades of sectarian violence known as the Troubles.