July 31

Vlad III, later known as Vlad the Impaler, becomes voivode of Wallachia for the first time.

Vlad III, later infamous as Vlad the Impaler and a partial inspiration for the fictional Dracula, became voivode, or ruling prince, of Wallachia for the first of what would be several turbulent reigns marked by brutal methods of enforcing order and resisting Ottoman expansion.

Spain's Alhambra Decree takes effect, expelling practicing Jews who refuse conversion from the kingdom.

Spain's Catholic monarchs enforced their earlier Alhambra Decree, requiring practicing Jews who had not converted to Christianity to leave the kingdom or face execution, resulting in the expulsion of tens of thousands of people and the loss of a centuries-old Jewish community from Spanish society.

Christopher Columbus becomes the first European to sight the island of Trinidad during his third voyage.

During his third voyage westward, Christopher Columbus became the first European recorded to sight the island of Trinidad off the coast of present-day Venezuela, part of a journey that also brought him into contact with the South American mainland for the first time.

Aurangzeb is crowned Mughal emperor of India after defeating his brothers in a war of succession.

After a bitter war of succession against his brothers following their father's illness, Aurangzeb was formally crowned Mughal emperor of India, going on to rule for nearly five decades and expand the empire to its greatest territorial extent, though his reign also sowed seeds of later imperial decline.

The Marquis de Lafayette, aged just 19, is commissioned as a major general in the Continental Army.

At just nineteen years old, the French aristocrat Marquis de Lafayette received a commission as a major general in the Continental Army, having volunteered to support the American cause without pay. He became a trusted aide to George Washington and a lasting symbol of French-American friendship.

The United States issues its first patent, granted to Samuel Hopkins for a potash production process.

Samuel Hopkins received the first patent ever issued by the newly formed United States federal government, covering an improved industrial process for producing potash, a chemical compound widely used at the time in fertilizer and soap manufacturing. The patent was signed personally by President George Washington.

The city of Christchurch, New Zealand, is officially established.

British colonial settlers formally established the city of Christchurch on New Zealand's South Island, planned as an Anglican settlement modeled on English cathedral cities. It later grew into one of New Zealand's largest urban centers, retaining strong architectural and cultural ties to its English colonial origins.

The long-running American radio drama "The Shadow" airs for the first time.

The long-running American radio drama "The Shadow," featuring a mysterious crime-fighter with the power to cloud men's minds, made its broadcast debut, later helping launch the career of actor Orson Welles, who voiced the title character during part of the show's popular run.

NASA's Ranger 7 probe transmits the first close-up photographs of the Moon's surface before its planned impact.

After traveling roughly 70 million miles through space, NASA's Ranger 7 probe transmitted the first close-up photographs of the Moon's surface before deliberately crashing into it, providing scientists with dramatically more detailed lunar imagery than any earlier mission and informing planning for future crewed landings.

Apollo 15 astronauts David Scott and James Irwin take the Lunar Roving Vehicle on its first drive across the Moon's surface.

Apollo 15 astronauts David Scott and James Irwin took the mission's battery-powered Lunar Roving Vehicle out for its first drive across the lunar surface, dramatically extending the range of their exploration compared to earlier missions that had required astronauts to travel entirely on foot.