On This Day in History: June 1

The Roman Republic was established after the overthrow of the Roman monarchy around 509 BCE following the overthrow of the last king, Lucius Tarquinius Superbus, replacing the monarchy with a representative government. This transition marked a shift to a system led by two annually elected consuls and the Senate, lasting until 27 BCE. Expand +

Alfonso X inherits the throne and becomes King of Castile, León, and Galicia, on June 1, 1252, upon the death of his father, Ferdinand III. His reign, from 1252 to 1284, was marked by a focus on culture, law, and science.

The Treaty of Rheinfelden (or Rheinfelder Hausordnung) was signed on June 1, 1283, in the Imperial City of Rheinfelden. It established the Habsburg order of succession, confirming Duke Albert, son of Rudolph I as the sole ruler of the Austrian and Styrian duchies and removing his brother, Rudolf II, as co-ruler.

Ottoman Turks led by Osman I begin the Ottoman Empire's expansion from their base in Anatolia, starting with the Byzantine lands in western Anatolia and later expanding into the Balkans and beyond. Expand +

The Battle of San Romano was fought on June 1, 1432, between the Republic of Florence, led by Niccolò da Tolentino, and the Republic of Siena, under Francesco Piccinino. It took place near San Romano, a town approximately 30 miles outside Florence, Italy. Expand +

The University of Copenhagen is officially inaugurated in Denmark on June 1, 1479 at a ceremony in the Church of Our Lady. The University opened with the traditional medieval faculties of theology, law, medicine and philosophy. It is Denmark's oldest university and a leading research institution.

The Myles Standish Burial Ground (or Old Burying Ground) in Duxbury, Massachusetts, was established around 1638. It is the oldest continuously maintained cemetery in the United States, according to the American Cemetery Association. It is the final resting place for many Pilgrims, including ,John Alden, the Mayflower's first recorded burial and his wife Priscilla Alden and Myles Standish Expand +

The battle at Öland takes place on June 1, 1676, in the Baltic Sea, off the east coast of Öland during the Scanian War,. The battle resulted in the defeat of the Swedish navy by the allied Danish-Dutch forces. More

Kentucky was admitted to the United States Unionion on June 1, 1792, becoming the 15th State. and the first state west of the Appalachian Mountains. Originally part of Virginia's western territory, the region separated to become a state following congressional approval More

Tennessee was admitted to the U.S on June 1, 1796, becoming the 16th State and the first State to be carved from federal territory. Known as the "Southwest Territory" prior to statehood, the area was admitted after a census and a constitutional convention held in Knoxville.More

The island of Crete falls to Nazi German forces, on June 1, 1941 during WWII, after an almost two week-long battle, despite fierce resistance from Allied troops and Cretan civilians. The battle involved intense air bombardment and airborne assaults by German paratroopers and glider troops.

Western Samoan islands independence day. The Western Samoan Islands became independent from New Zealand on January 1, 1962, as Western Samoa, later known as Samoa, but its independence day is celebrated on June 1, to avoid it coinciding with New Year's Day and to allow for better weather for the celebrations, since January falls in the rainy season.

Cincinnati surgeon Henry J. Heimlich publishes, his stop-choking technique, on June 1, 1974, in the medical journal Emergency Medicine. The technique, now called, the Heimlich maneuver, involved thrusting inward and upward on the abdomen of choking victims and It quickly became a go-to method for saving those lives.  Expand +

CNN, headquartered in Atlanta, debuts its 24-hour live news broadcasts, on June 1, 1980, from its headquarters in Atlanta, Georgia. It went on, in 1991 to gain worldwide attention for its around-the-clock coverage of the Persian Gulf War. More

,George H.W. Bush and Soviet leader Mikhail Gorbachev sign a bilateral agreement , on June 1, 1990, on Destruction and Non-production of Chemical Weapons and on Measures to Facilitate the Multilateral Convention on Banning Chemical Weapons". Expand +

The European Central Bank is established, on June 1, 1998, leading to the introduction of the euro currency. The first President of the Bank was Wim Duisenberg, the former president of the Dutch central bank and the European Monetary Institute.