The ancient kingdom of Urartu arose in the ninth century B.C. in the region that later became Armenia. It rivaled Assyria until defeated by that power in 714 B.C. Following a period of decline, Urartu was conquered in the sixth century B.C. by the Medes and then by the Persians. With Urartu's fall, the Armenians, an Indo-European people, settled in the region as overlords.

In the fourth century B.C., Alexander the Great destroyed the Persian Empire, and Armenia won autonomy under the Greek Seleucid Kingdom, one of the states that succeeded Alexander's empire. In 190 B.C., Armenia regained independence. Under King Tigranes I (95-56 B.C.), Armenia reached the zenith of its power, covering an area that included what is now the Armenian republic, northwestern Iran, northern Iraq, eastern Turkey, Lebanon, and most of Syria. During 69-34 B.C., Roman armies conquered Armenia. It served as a buffer state between the Roman Empire and Persia.

About 300 A.D., Armenia became the first nation to accept Christianity. The Armenian alphabet was invented about 400. With the decline of the Roman Empire in the fifth century, Armenia fell under Sassanid Persian domination.

In 652, the Muslim Arabs conquered Armenia, but allowed the Armenians to govern themselves. In 1064 Armenia was invaded by the Seljuk Turks. Many Armenians fled to the southern coast of Asia Minor, where they set up an independent state called Little Armenia; it survived until the 14th century. In the 16th century, Armenia was conquered by the Ottoman Turks.

Eastern Armenia was ceded to Persia in the 17th century, and the northern section to Russia in the 19th. Agitation for independence in Turkish Armenia led, in the 1890's, to a series of government-inspired massacres in which thousands of Christian Armenians lost their lives. Fearing treachery from the Armenians in World War I, the Turkish government made an effort to rid the empire of them by murder and deportation. By the end of the war between 1,000,000 and 1,500,000 Armenians had been killed by the Turks or had perished during deportation; only a handful remained in Turkey.

Russian-held Armenia became independent after the Russian Revolution in 1917 but was rejoined to Russia in 1920. In 1922 Armenia, Georgia, and Azerbaijan were organized into the Transcaucasian Soviet Federal Socialist Republic. This arrangement ended in 1936 and Armenia became a union republic of the Soviet Union.

In 1988 an earthquake killed about 25,000 people in Armenia. Also that year, fighting broke out between Azerbaijanis and Armenians living in Nagorno-Karabakh, a predominantly Armenian region within Azerbaijan. During 1990-91, rising nationalism throughout the union republics gradually eroded the authority of the Soviet central government. In 1990, the Armenian National Movement won a majority of the seats in parliament and formed a government. After the Soviet Union collapsed in 1991, Armenia once again became independent. Also that year, Armenia joined the Commonwealth of Independent States. Fighting between the Azerbaijanis and Armenians over Nagorno-Karabakh continued and in 1993 the Armenians captured all of the region. In the spring of 1994, a cease-fire agreement was negotiated. In 1995 Armenia adopted a new constitution.

Levon Ter-Petrosyan, who had been president since 1991, resigned in 1998 after accusations of fraud in Armenia's 1996 elections. Prime minister Robert Kocharian succeeded Ter-Petrosyan and won the presidential elections in 1998 and 2003.