In History, Today on September 23

The Concordat of Worms was signed, ending the Investiture Controversy between the Papacy and the Holy Roman Empire.

The Battle of Blore Heath, part of the Wars of the Roses, took place in England, resulting in a victory for the Yorkists.

The first commencement exercises were held at Harvard College, the first institution of higher learning in the United States.

Lewis and Clark Expedition returned to St. Louis after exploring the Pacific Northwest.

German astronomer Johann Gottfried Galle discovered the planet Neptune, based on predictions by Urbain Le Verrier.

Nintendo Koppai, later known as Nintendo Company, Limited, was founded by Fusajiro Yamauchi in Kyoto, Japan.

The Kingdom of Saudi Arabia was unified by King Abdulaziz Ibn Saud, marking the establishment of the modern state.

The Italian Social Republic was founded under Benito Mussolini, following the armistice between Italy and Allied forces.

Richard Nixon delivered his "Checkers speech" on television, defending himself against accusations of improper campaign funding.

The Lincoln Center for the Performing Arts opened in New York City, becoming a major cultural venue.

Bob Marley performed his last concert at the Stanley Theatre in Pittsburgh, Pennsylvania, before his death in 1981.

NASA announced that it had lost contact with the Mars Climate Orbiter due to a metric conversion error.

The first public version of the web browser Mozilla Firefox, then known as Phoenix 0.1, was released.

Hurricane Jeanne made landfall in Haiti, causing severe flooding and landslides that resulted in over 3,000 deaths.

The Large Hadron Collider (LHC) at CERN was officially inaugurated, marking a significant milestone in particle physics research.

Palestinian President Mahmoud Abbas submitted Palestine's application for full membership in the United Nations.

Volkswagen CEO Martin Winterkorn resigned amid the emissions scandal, where the company was found to have cheated on diesel emissions tests.

Greta Thunberg delivered a powerful speech at the United Nations Climate Action Summit, urging world leaders to take immediate action against climate change.