THE Holocaust was the systematic, bureaucratic, state-sponsored persecution and murder of approximately six million Jews by the German Nazi regime and its collaborators.

Holocaust is a word of Greek origin meaning "sacrifice by fire".

The Nazis, who came to power in Germany in January 1933, believed that Germans were "racially superior" and that the Jews, deemed inferior, were "life unworthy of life".

During the Holocaust, the Nazis also targeted other groups because of their perceived "racial inferiority": Roma (Gypsies), the handicapped, and some of the Slavic peoples (Poles, Russians, and others).

Other groups were persecuted on political and behavioural grounds, among them Communists, Socialists, Jehovah's Witnesses, and homosexuals. In 1933, the Jewish population of Europe stood at more than nine million.

Most European Jews lived in countries that Germany would occupy or influence during World War II. By 1945, close to two out of every three European Jews had been killed as part of the "Final Solution", the Nazi policy to murder the Jews of Europe.

Although Jews made up the largest numbers of those killed by the Nazis, an estimated 10s of thousands of Roma and at least 200,000 mentally or physically disabled people were murdered in the Euthanasia Program.

As Nazi tyranny spread across Europe, the Nazis persecuted and murdered millions of other people. More than three million Soviet prisoners of war were murdered or died of starvation, disease, neglect, or maltreatment.

The Germans targeted the non-Jewish Polish intelligentsia for killing, and deported millions of Polish and Soviet citizens for forced labour in Germany or in occupied Poland.

From the earliest years of the Nazi regime, homosexuals and others deemed to be behaving in a socially unacceptable way were persecuted.

Thousands of political dissidents (including Communists, Socialists, and trade unionists) and religious dissidents (such as Jehovah's Witnesses) were also targeted.

Before the war the Nazis established concentration camps to imprison Jews, Roma, other victims of ethnic and racial hatred, and political opponents of Nazism. During the war years, the Nazis and their collaborators created ghettos, transit camps, and forced-labour camps.

Following the invasion of the Soviet Union in June 1941, Einsatzgruppen (mobile killing units) carried out mass-murder operations against Jews, Roma, and Soviet state and Communist party officials. More than a million Jewish men, women, and children were murdered by these units.

Between 1942 and 1944, Nazi Germany deported millions more Jews from the occupied territories to extermination camps, where they murdered them in specially developed killing facilities.

In the final months of the war, SS guards forced camp inmates on death marches in an attempt to prevent the Allied liberation of large numbers of prisoners.

As Allied forces moved across Europe in a series of offensives on Germany, they began to encounter and liberate concentration camp prisoners, many of whom had survived the death marches.

In many cases Allied troops, horrified by what they found, forced German civilians from nearby towns and villages to walk through the camps to see for themselves the inhumanities carried out in their name.

Victims of Holocaust were always civilians, including women and children, or unarmed prisoners of war, not armed soldiers killed in battle.