On this day: 30 March

Guru Gobind Singh establishes the Khalsa in Anandpur Sahib, Punjab.

Joachim Murat, King of Naples, issued the Rimini Proclamation, among the earliest calls for Italian unification.

Physicist Augustin Fresnel reads a memoir on optical rotation to the French Academy of Sciences, reporting that when polarized light is "depolarized" by a Fresnel rhomb, its properties are preserved in any subsequent passage through an optically-rotating crystal or liquid.

The United States merged East Florida and West Florida to create the Florida Territory.

The National Bank of Greece is founded in Athens.

Ether anesthesia is used for the first time, in an operation by the American surgeon Dr. Crawford Long.

One of the most important battles of the Dominican War of Independence from Haiti takes place near the city of Santiago de los Caballeros.

Origins of the American Civil War: "Border Ruffians" from Missouri invade Kansas and force election of a pro-slavery legislature.

The Treaty of Paris is signed, ending the Crimean War.

U.S. secretary of state William H. Seward negotiated the purchase of Alaska from Russia for US$7.2 million.

Texas is readmitted to the United States Congress following Reconstruction.

German Society of Chemistry issues an invitation to other national scientific organizations to appoint delegates to the International Committee on Atomic Weights.

Archaeologists in Knossos, Crete, discover the first clay tablet with hieroglyphic writing in a script later called Linear B.

Sultan Abd al-Hafid signed the Treaty of Fes, making Morocco a French protectorate.

The Australian Air Corps was disbanded, to be replaced the following day by the Australian Air Force.

The Heinkel He 100 fighter sets a world airspeed record of 463 mph (745 km/h).

Second Sino-Japanese War: Japan declares Nanking capital of a new Chinese puppet government, nominally controlled by Wang Jingwei.

World War II: Soviet forces invade Austria and capture Vienna. Polish and Soviet forces liberate Danzig.

Tenzin Gyatso, the 14th Dalai Lama, flees Tibet for India.

Jeopardy!, the popular American game show created by Merv Griffin, made its debut on the NBC television network.

Vietnam War: North Vietnamese forces began the Easter Offensive in an attempt to gain as much territory and destroy as many South Vietnamese units as possible.

Israeli-Palestinian conflict: in the first organized response against Israeli policies by a Palestinian collective since 1948, Palestinians create the first Land Day.

Annie Hall had its first screening at the LA Film Festival; it was voted the funniest screenplay ever by members of the Writers Guild of America.

Space Shuttle program: STS-3 mission is completed with the landing of Columbia at White Sands Missile Range, New Mexico.

Cyclone Glenda, one of the strongest tropical cyclones in the Australian region makes landfall near Onslow, Western Australia.

Min Aung Hlaing is appointed as the Commander-in-Chief of Myanmar's armed forces.

SpaceX conducts the world's first reflight of an orbital class rocket.

Pope Francis visits Morocco.

Donald Trump became the first former U.S. president to be indicted by a grand jury.