One of the world's oldest civilizations, Armenia once included Mount Ararat, which biblical tradition identifies as the mountain that Noah's ark rested on after the flood. It was the first country in the world to officially embrace Christianity as its religion (c. A.D. 300).

In the 6th century B.C., Armenians settled in the kingdom of Urartu (the Assyrian name for Ararat), which was in decline. Under Tigrane the Great (fl. 95–55 B.C.) the Armenian empire reached its height and became one of the most powerful in Asia, stretching from the Caspian to the Mediterranean seas. Throughout most of its long history, however, Armenia has been invaded by a succession of empires. Under constant threat of domination by foreign forces, Armenians became both cosmopolitan as well as fierce protectors of their culture and tradition.

Over the centuries Armenia was conquered by Greeks, Romans, Persians, Byzantines, Mongols, Arabs, Ottoman Turks, and Russians. From the 16th century through World War I, major portions of Armenia were controlled by their most brutal invader, the Ottoman Turks, under whom the Armenians experienced discrimination, religious persecution, heavy taxation, and armed attacks. In response to Armenian nationalist stirrings, the Turks massacred thousands of Armenians in 1894 and 1896. The most horrific massacre took place in April 1915 during World War I, when the Turks ordered the deportation of the Armenian population to the deserts of Syria and Mesopotamia. According to the majority of historians, between 600,000 and 1.5 million Armenians were murdered or died of starvation. The Armenian massacre is considered the first genocide in the 20th century. Turkey denies that a genocide took place and claims that a much smaller number died in a civil war.

After the Turkish defeat in World War I, the independent Republic of Armenia was established on May 28, 1918, but survived only until Nov. 29, 1920, when it was annexed by the Soviet army. On March 12, 1922, the Soviets joined Georgia, Armenia, and Azerbaijan to form the Transcaucasian Soviet Socialist Republic, which became part of the USSR. In 1936, after a reorganization, Armenia became a separate constituent republic of the USSR. Armenia declared its independence from the collapsing Soviet Union on Sept. 23, 1991.

In 1988, Armenia became involved in a territorial dispute with Azerbaijan over the enclave of Nagorno-Karabakh, to which both laid claim. The majority of the enclave were Armenian Christians who wanted to secede from Azerbaijan and either become part of Armenia or gain full independence. War broke out between Armenia and Azerbaijan over the region from 1992–1994, resulting in 30,000 casualties. Armenia effectively controls the region today, although no formal resolution exists.

An Armenian diaspora has existed throughout the nation's history, and Armenian emigration has been particularly heavy since independence from the Soviet Union. An estimated 60% of the total 8 million Armenians worldwide live outside the country, with 1 million each in the U.S. and Russia. Other significant Armenian communities are located in Georgia, France, Iran, Lebanon, Syria, Argentina, and Canada.

Prime Minister Andranik Markarian died suddenly in March 2007. He was replaced by Defense Minister Serzh Sarkisyan.

Sarkisyan won almost 53% of the vote and former president Levon Ter-Petrosyan took 21.5% in February 2008 presidential elections. Ter-Petrosyan, who was Armenia's first president after it gained independence in 1991, claimed the vote was rigged. Tens of thousands of his supporters took to the streets in Yerevan to protest the election. A 20-day state of emergency was declared on March 1 when the protests turned violent and eight people were killed. On March 22, the state of emergency ended and troops left the capital.

On April 9, 2008, Serzh Sarkisyan was sworn in as president and named Tigran Sarkisyan as prime minister. They are not related.