1291 The Swiss Confederation is formed with the signature of the Federal Charter.
1349 The Jewish population of Basel, Switzerland, believed by the residents to be the cause of the ongoing Black Death, is rounded up and incinerated.
1422 Battle of Arbedo between the duke of Milan and the Swiss cantons.
1499 Treaty of Basel: Switzerland becomes an independent state.
1500 Ludovico Sforza is captured by the Swiss troops at Novara and is handed over to the French.
1513 Italian Wars: Battle of Novara. Swiss troops defeat the French under Louis de la Tremoille, forcing the French to abandon Milan. Duke Massimiliano Sforza is restored.
1525 The Swiss Anabaptist Movement is founded when Conrad Grebel, Felix Manz, George Blaurock, and about a dozen others baptize each other in the home of Manz's mother in Zürich, breaking a thousand-year tradition of church-state union.
1531 The Second war of Kappel results in the dissolution of the Protestant alliance in Switzerland.
1799 War of the Second Coalition: Austrian forces defeats the French at Winterthur, Switzerland, securing control of the northeastern Swiss Plateau because of the town's loaction at the junction of seven cross-roads.
1809 The Swiss canton of Aargau denies citizenship to Jews.
1845 The Sonderbund is defeated by the joint forces of other Swiss cantons under General Guillaume-Henri Dufour.
1848 Switzerland becomes a Federal state.
1917 Lenin returns to Petrograd from exile in Switzerland.
1923 The Treaty of Lausanne, settling the boundaries of modern Turkey, is signed in Switzerland by Greece, Bulgaria and other countries that fought in World War I.
1932 Riots between conservative and socialist supporters in Switzerland kill 12 and injure 60.
1935 Switzerland: A Royal Dutch Airlines plane en route from Milan to Frankfurt crashes into a Swiss mountain, killing thirteen.
1938 LSD is first synthesized by Swiss chemist Dr. Albert Hofmann at the Sandoz Laboratories in Basel, Switzerland.
1939 Switzerland mobilizes its forces and the Swiss Parliament elects Henri Guisan to head the Swiss Army (an event that can happen only during war or mobilization).
1943 ''Bicycle Day'' – Swiss chemist Dr. Albert Hofmann deliberately takes LSD for the first time.
1944 Navigation errors lead to an accidental American bombing of the Swiss city of Schaffhausen.
1946 Diplomatic relations between Switzerland and the Soviet Union are established.
1948 Swiss chemist Paul Müller is awarded the Nobel Prize in Physiology or Medicine for his discovery of the insecticidal properties of DDT.
1950 Bhumibol Adulyadej marries Queen Sirikit after their quiet engagement in Lausanne, Switzerland on July 19, 1949.
1954 UEFA (Union des Associations Européennes de Football) is formed in Basel, Switzerland.
1956 First ascent of Lhotse 8,516 metres, by a Swiss team.
1956 The first Eurovision Song Contest is held in Lugano, Switzerland
1963 Swissair Flight 306 crashes near Dürrenäsch, Switzerland, killing all 80 people on board.
1970 Swissair Flight 330: A mid-air bomb explosion and subsequent crash kills 38 passengers and nine crew members near Zürich, Switzerland.
1971 The Montreux Casino in Switzerland is set ablaze by someone wielding a flare gun during a Frank Zappa concert; the incident would be noted in the Deep Purple song "Smoke on the Water".
1988 In a United Nations ceremony in Geneva, Switzerland, the Soviet Union signs an agreement pledging to withdraw its troops from Afghanistan.
1997 The so-called Big Three banks in Switzerland announce the creation of a $71 million fund to aid Holocaust survivors and their families.
1998 While ''en route'' from Adana to Ankara, a Turkish Airlines flight with a crew of 6 and 33 passengers is hijacked by a Kurdish militant who orders the pilot to fly to Switzerland. The plane instead lands in Ankara after the pilot tricked the hijacker into thinking that he is landing in the Bulgarian capital of Sofia to refuel.
2002 Citizens of Switzerland narrowly vote in favor of their country becoming a member of the United Nations.
2002 Switzerland, traditionally a neutral country, joins the United Nations.
2008 The Large Hadron Collider at CERN, described as the biggest scientific experiment in history is powered up in Geneva, Switzerland.