In History, Today on March 21

Kazakhstan's capital was renamed from Astana to Nur-Sultan in honor of the former president Nursultan Nazarbayev.

United States President Barack Obama makes a historic visit to Cuba, being the first sitting U.S. president to visit the island nation in 88 years, signaling a thaw in relations between the two countries.

Russia formally annexed Crimea after a controversial referendum, escalating tensions with Ukraine and Western countries.

The European Space Agency launched the Planck satellite to study the Cosmic Microwave Background, providing insights into the early universe.

The Syrian government launched a major offensive against opposition forces in the city of Homs, marking a significant escalation in the Syrian Civil War.

The Syrian Civil War began with nationwide protests against President Bashar al-Assad's government, part of the wider wave of the Arab Spring.

The U.S. House of Representatives passes the Patient Protection and Affordable Care Act.

A Palestinian gunman kills eight students at the Mercaz HaRav yeshiva in Jerusalem.

Twitter was founded by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams, marking the beginning of a new era in social media communication.

The United States and coalition forces launched a ground invasion of Iraq, marking the beginning of the Iraq War.

Bertrand Piccard and Brian Jones became the first aviators to circumnavigate the globe non-stop in a balloon.

Namibia gained independence from South Africa, marking the end of a long struggle for freedom and the beginning of a new chapter as a sovereign nation.

U.S. President Jimmy Carter announced a boycott of the 1980 Summer Olympics in Moscow in response to the Soviet invasion of Afghanistan. This decision led to a significant number of countries joining the boycott.

Martin Luther King Jr. led 3,200 people on the start of the third and finally successful civil rights march from Selma to Montgomery, Alabama.

Alcatraz Federal Penitentiary, located on Alcatraz Island in San Francisco Bay, was closed. The prison had been operational since 1934 and was known for housing some of America's most notorious criminals.

The Sharpeville massacre occurred in South Africa when police opened fire on a crowd of black protesters, killing 69 people. The protest was against the apartheid pass laws, and the event became a turning point in the struggle against apartheid.

The Shah of Iran, Reza Shah Pahlavi, formally asked the international community to refer to the country as Iran instead of Persia, a move he initiated to foster a sense of nationalism and emphasize the country's historical legacy.

Charles Lindbergh was presented with the Medal of Honor by President Calvin Coolidge for his transatlantic flight in 1927, recognizing his contributions to aviation and inspiring public enthusiasm for air travel.

The German Spring Offensive, also known as the Kaiserschlacht, began during World War I. It was a series of German attacks along the Western Front, marking the last major German offensive of the war.

The London-based British East Africa Company surrenders its administrative rights of Uganda to the British government.

A major railway collision occurs in Montparnasse, Paris, resulting in a public outcry and reforms in train safety protocols.

The first performance of Modest Mussorgsky's opera 'Khovanshchina' takes place in St. Petersburg.

Journalist Henry Morton Stanley began his famous expedition to find the missing explorer and missionary David Livingstone in Africa.

An earthquake strikes Tokyo, then known as Edo, with significant destruction.

The Bahá'í calendar, also known as the Badíʿ calendar, began. It is a solar calendar with 19 months of 19 days each, plus an additional period of 'Intercalary Days' to adjust to the solar year. This calendar is used by followers of the Bahá'í Faith.

The Napoleonic Code, a fundamental set of laws for France, was enacted. It served as a major influence on civil law codes worldwide.

The Battle of Heliopolis took place during the French Revolutionary Wars, where French forces under General Jean-Baptiste Kléber defeated the Ottoman army near Cairo, Egypt. This battle was part of the French campaign in Egypt and Syria.

Thomas Cranmer, the former Archbishop of Canterbury, was executed for heresy under the reign of Queen Mary I of England. His execution marked a significant moment in the Marian Persecutions, which aimed to restore Roman Catholicism in England.

During the First Crusade, Baldwin of Boulogne is crowned the first Count of Edessa, solidifying the capture and establishment of the County of Edessa as the first of the Crusader states.

Theodosius III, Byzantine Emperor, abdicated the throne in favor of Leo III the Isaurian, marking the beginning of the Isaurian dynasty.

The Byzantine Emperor Heraclius restored the True Cross to Jerusalem, which had been captured by the Sassanid Empire in 614. This event was significant in the context of the Byzantine-Sassanid Wars.

The death of Saint Benedict of Nursia, the founder of the Benedictine monastic order, occurred. He is known for establishing the Rule of Saint Benedict, which became a foundational text for Western monasticism.