According to folklore, Tutsi cattlebreeders began arriving in the area from the Horn of Africa in the 15th century and gradually subjugated the Hutu inhabitants. The Tutsis established a monarchy headed by a mwami (king) and a feudal hierarchy of Tutsi nobles and gentry. Through a contract known as ubuhake, the Hutu farmers pledged their services and those of their descendants to a Tutsi lord in return for the loan of cattle and use of pastures and arable land. Thus, the Tutsi reduced the Hutu to virtual serfdom. However, boundaries of race and class became less distinct over the years as some Tutsi declined until they enjoyed few advantages over the Hutu. The first European known to have visited Rwanda was German Count Von Goetzen in 1894. He was followed by missionaries, notably the "White Fathers." In 1899, the mwami submitted to a German protectorate without resistance. Belgian troops from Zaire chased the small number of Germans out of Rwanda in 1915 and took control of the country.

After World War I, the League of Nations mandated Rwanda and its southern neighbor, Burundi, to Belgium as the territory of Ruanda-Urundi. Following World War II, Ruanda-Urundi became a UN Trust Territory with Belgium as the administrative authority. Reforms instituted by the Belgians in the 1950s encouraged the growth of democratic political institutions but were resisted by the Tutsi traditionalists who saw in them a threat to Tutsi rule. An increasingly restive Hutu population, encouraged by the Belgian military, sparked a revolt in November 1959, resulting in the overthrow of the Tutsi monarchy. Two years later, the Party of the Hutu Emancipation Movement (PARMEHUTU) won an overwhelming victory in a UN-supervised referendum.

During the 1959 revolt and its aftermath, more than 160,000 Tutsis fled to neighboring countries. The PARMEHUTU government, formed as a result of the September 1961 election, was granted internal autonomy by Belgium on January 1, 1962. A June 1962 UN General Assembly resolution terminated the Belgian trusteeship and granted full independence to Rwanda (and Burundi) effective July 1, 1962.

Gregoire Kayibanda, leader of the PARMEHUTU Party, became Rwanda's first elected president, leading a government chosen from the membership of the directly elected unicameral National Assembly. Peaceful negotiation of international problems, social and economic elevation of the masses, and integrated development of Rwanda were the ideals of the Kayibanda regime. Relations with 43 countries, including the United States, were established in the first 10 years. Despite the progress made, inefficiency and corruption began festering in government ministries in the mid-1960s. On July 5, 1973, the military took power under the leadership of Maj. Gen. Juvenal Habyarimana, who dissolved the National Assembly and the PARMEHUTU Party and abolished all political activity.

In 1975, President Habyarimana formed the National Revolutionary Movement for Development (MRND) whose goals were to promote peace, unity, and national development. The movement was organized from the "hillside" to the national level and included elected and appointed officials.

Under MRND aegis, Rwandans went to the polls in December 1978, overwhelmingly endorsed a new constitution, and confirmed President Habyarimana as president. President Habyarimana was re-elected in 1983 and again in 1988, when he was the sole candidate. Responding to public pressure for political reform, President Habyarimana announced in July 1990 his intention to transform Rwanda's one-party state into a multi-party democracy.

On October 1, 1990, Rwandan exiles banded together as the Rwandan Patriotic Front (RPF) and invaded Rwanda from their base in Uganda. The rebel force, composed primarily of ethnic Tutsis, blamed the government for failing to democratize and resolve the problems of some 500,000 Tutsi refugees living in diaspora around the world. The war dragged on for almost 2 years until a cease-fire accord was signed July 12, 1992, in Arusha, Tanzania, fixing a timetable for an end to the fighting and political talks, leading to a peace accord and powersharing, and authorizing a neutral military observer group under the auspices of the Organization for African Unity. A cease-fire took effect July 31, 1992, and political talks began August 10, 1992.

On April 6, 1994, the airplane carrying President Habyarimana and the President of Burundi was shot down as it prepared to land at Kigali. Both presidents were killed. As though the shooting down was a signal, military and militia groups began rounding up and killing all Tutsis and political moderates, regardless of their ethnic background.

The prime minister and her 10 Belgian bodyguards were among the first victims. The killing swiftly spread from Kigali to all corners of the country; between April 6 and the beginning of July, a genocide of unprecedented swiftness left up to 800,000 Tutsis and moderate Hutus dead at the hands of organized bands of militia--Interahamwe. Even ordinary citizens were called on to kill their neighbors by local officials and government-sponsored radio. The president's MRND Party was implicated in organizing many aspects of the genocide.

The RPF battalion stationed in Kigali under the Arusha accords came under attack immediately after the shooting down of the president's plane. The battalion fought its way out of Kigali and joined up with RPF units in the north. The RPF then resumed its invasion, and civil war raged concurrently with the genocide for 2 months. French forces landed in Goma, Zaire, in June 1994 on a humanitarian mission. They deployed throughout southwest Rwanda in an area they called "Zone Turquoise," quelling the genocide and stopping the fighting there. The Rwandan Army was quickly defeated by the RPF and fled across the border to Zaire followed by some 2 million refugees who fled to Zaire, Tanzania, and Burundi. The RPF took Kigali on July 4, 1994, and the war ended on July 16, 1994. The RPF took control of a country ravaged by war and genocide. Up to 800,000 had been murdered, another 2 million or so had fled, and another million or so were displaced internally.

The international community responded with one of the largest humanitarian relief efforts ever mounted. The United States was one of the largest contributors. The UN peacekeeping operation, UNAMIR, was drawn down during the fighting but brought back up to strength after the RPF victory. UNAMIR remained in Rwanda until March 8, 1996.

Following an uprising by the ethnic Tutsi Banyamulenge people in eastern Zaire in October 1996, a huge movement of refugees began which brought more than 600,000 back to Rwanda in the last 2 weeks of November. This massive repatriation was followed at the end of December 1996 by the return of another 500,000 from Tanzania, again in a huge, spontaneous wave. Less than 100,000 Rwandans are estimated to remain outside of Rwanda, and they are thought to be the remnants of the defeated army of the former genocidal government, its allies in the civilian militias known as Interahamwe, and soldiers recruited in the refugee camps before 1996.

With the return of the refugees, a new chapter in Rwandan history began. As of October 2003, Rwanda’s refugee population consisted of 28,000 Congolese Tutsis at two camps in Kibuye and Byumba provinces. In 2001, the government began implementation of a grassroots village-level justice system, known as gacaca, in order to address the enormous backlog of cases. As of October 2003, some 80,000 individuals remained in detention in Rwanda, awaiting gacaca trials on charges relating to the 1994 genocide.