During the First Crusade, Christian knights from Europe capture Jerusalem after seven weeks of siege and begin massacring the city’s Muslim and Jewish population.

Although there is some debate about the exact date, on what was likely July 15, 1799, during Napoleon Bonaparte’s Egyptian campaign, a French soldier discovers a black basalt slab inscribed with ancient writing near the town of Rosetta, about 35 miles east of Alexandria. The irregularly shaped stone contained fragments of passages written in three different scripts: Greek, Egyptian hieroglyphics and Egyptian demotic. The ancient Greek on the Rosetta Stone told archaeologists that it was inscribed by priests honoring the king of Egypt, Ptolemy V, in the second century B.C. More startlingly, the Greek passage announced that the three scripts were all of identical meaning. The artifact thus held the key to solving the riddle of hieroglyphics, a written language that had been “dead” for nearly 2,000 years.

On July 15, 1903, the newly formed Ford Motor Company takes its first order from Chicago dentist Ernst Pfenning: an $850 two-cylinder Model A automobile with a tonneau (or backseat). The car, produced at Ford’s plant on Mack Street (now Mack Avenue) in Detroit, was delivered to Dr. Pfenning just over a week later.

On July 15, 1918, near the Marne River in the Champagne region of France, the Germans begin what would be their final offensive push of World War I. Dubbed the Second Battle of the Marne, the conflict ended several days later in a major victory for the Allies.

The unmanned spacecraft Mariner 4 passes over Mars at an altitude of 6,000 feet and sends back to Earth the first close-up images of the red planet.

During a live television and radio broadcast, President Richard Nixon stuns the nation by announcing that he will visit communist China the following year. The statement marked a dramatic turning point in U.S.-China relations, as well as a major shift in American foreign policy.

On July 15, 1978, the “Longest Walk”—a 2,800-mile trek for Native American justice that had started with several hundred marchers in California in California—ends in Washington, D.C., accompanied by thousands of supporters. The intent of the event was to call attention to issues affecting Native Americans, such as a lack of jobs and housing, and legislation before Congress that could dramatically change their rights.

Johnny Cash’s 50-year country music career reaches a low point on July 15, 1986, when Columbia Records drops him from its roster after more than a quarter-century of history-making partnership, producing more than 60 albums.

On July 15, 2006, the San Francisco-based podcasting company Odeo officially releases Twttr—later changed to Twitter—its short messaging service (SMS) for groups, to the public.