20 March 1861

Taliban militants killed nine civilians in a mass shooting at the Kabul Serena Hotel in Afghanistan.

Eyjafjallajökull (pictured) in Iceland began a series of volcanic events, later disrupting air travel across Europe.

The Troubles: Two children were killed by the second of two bomb attacks by the Provisional Irish Republican Army in Warrington, England.

The antiretroviral drug zidovudine became the first treatment approved by the U.S. Food and Drug Administration for HIV/AIDS.

World War II: U.S. Marines made a landing on Emirau Island in the Bismarck Archipelago to develop an airbase as part of Operation Cartwheel.

World War II: After being forced to flee the Philippines for Australia, US Army general Douglas MacArthur announced: "I came through and I shall return."

Germany issued an ultimatum to Lithuania, demanding the return of the Klaipėda Region under threat of invasion.

Chiang Kai-shek initiated a purge of communist elements within the National Revolutionary Army in Guangzhou, China.

The Arts Club of Chicago hosted the opening of Pablo Picasso's first solo United States showing, entitled Original Drawings by Pablo Picasso.

The United States Navy commissioned its first aircraft carrier, USS Langley.

Emperor Wilhelm II dismissed Otto von Bismarck as the chancellor of the German Empire.

An earthquake occurred in the Argentine province of Mendoza, causing at least 6,000 deaths and destroying most of the buildings in the province's capital city.

Harriet Beecher Stowe's novel Uncle Tom's Cabin, which had a profound effect on attitudes toward African Americans and slavery in the United States, was published.

A fire of unknown cause broke out in Boston, Massachusetts, destroying 349 buildings.

Following the death of Pope Innocent XIII, a papal conclave convened in Rome to elect a new pope.

The Dutch East India Company, the first company to issue stock, was established.

La Plume noire, an anarchist bookstore in Lyon, is targeted by an attack of the far-right, provoking a shock in Lyon's far-left circles.

Kassym-Jomart Tokayev is sworn in as acting president of Kazakhstan, following the resignation of long-time president Nursultan Nazarbayev.

A solar eclipse, equinox, and a supermoon all occur on the same day.

Syrian civil war: The Siege of Kobanî is broken by the People's Protection Units (YPG) and Free Syrian Army (FSA), marking a turning point in the Rojava–Islamist conflict.

Four suspected Taliban members attack the Kabul Serena Hotel, killing at least nine people.

Eyjafjallajökull in Iceland begins eruptions that would last for three months, heavily disrupting air travel in Europe.

Over 150 Chadian soldiers are killed in eastern Chad by members of the rebel UFDC. The rebel movement sought to overthrow Chadian president Idriss Déby.

Iraq War: The United States, the United Kingdom, Australia, and Poland begin an invasion of Iraq.