After years as a German colony, Rwanda becomes a protectorate governed by Belgium and administered under a Tutsi monarch, who is recognized by both Tutsis and Hutus.
Belgians introduce a system of ethnic identity cards classifying everyone as either Hutu or Tutsi.
Hutus rebel against the Belgian colonial power and the Tutsi elite; more than 150,000 Tutsis flee to Burundi.  The Belgians switch their support to the Hutus.
The Tutsi monarchy is abolished by a referendum.  Rwanda gains independence from Belgium and the Hutu nationalist party comes to power.  Fighting continues and thousands of Tutsis are forced to flee.
Tutsis who fled in 1959 attack Rwanda from neighboring countries.  Tutsis in Rwanda are massacred and more refugees leave.
Hutu leaders purge Tutsis from their jobs in schools and universities.  Hutu Major Juvenal Habyarimana takes power and creates a one party state.   He sets ethnic quotas in public services, restricting Tutsis to nine percent of available jobs.  Violence and systematic exclusion of Tutsis continues throughout the '70s and '80s.
Rwandan exiles in Uganda form the Rwandan Patriotic Front (RPF), a Tutsi-dominated rebel military organization.
World coffee prices collapse.  Under pressure from Western aid donors, Habyarimana agrees to allow a multi-party system.  In October, RPF forces invade Rwanda from Uganda, starting a civil war.  
Habyarimana signs a cease-fire between the Rwandan Army (FAR) and the RPF.  Negotiations begin for a power-sharing agreement.   The Rwandan army begins to train and arm civilian militias (“interahamwe” - those who stand together).  As negotiations stall, Tutsis are periodically killed, tensions rise between Hutu moderates and extremists, and opposition politicians and newspapers are persecuted.
Habyarimana signs a power-sharing arrangement with the Tutsis and the UN sends a mission to monitor the peace agreement.   For the next year, progress stalls on implementing the power-sharing while political and ethnic tensions increase.  RTLM (Radio Télévison des Milles Collines) begins broadcasting extremist hate messages against Tutsis.
April 6 - Habyarimana and the President of Burundi are killed when their plane is shot down over Kigali.  Hutu extremists blame Tutsis for the attack and begin to massacre Tutsis that night.

April 7 – Factions of the Rwandan Army (FAR) and the interahamwe begin to systematically kill thousands of Tutsis and moderate Hutus.  U.N. forces are forbidden to intervene, as they are only allowed to ‘monitor’ the situation.

April/May -- 10 Belgian peacekeepers are killed; the UN reduces its forces in the country from 2,500 to 250. RPF launches a major offensive; extremist Hutu militia and elements of the Rwandan military begin the systematic massacre of Tutsis. Within 100 days, approximately 800,000 Tutsis and moderate Hutus are killed.

June-- The French establish a safe zone in the southwest corner of Rwanda.

July -- The Rwanda Genocide ends when the RPF reaches Kigali and takes control of the country.  Some reprisal killings by the RPF are reported. The Hutu government and militias flee to Zaire (now the DRC), taking with them over one million Hutu refugees.  250,000 remaining Tutsis flee to Tanzania and neighboring countries.  Killings of Tutsis and moderate Hutus continue in refugee camps.