International Holocaust Remembrance Day is commemorated every January 27. That’s the day, in 1945, when the Soviet army entered Auschwitz-Birkenau and liberated its prisoners.

Auschwitz-Birkenau was a Nazi-run death camp in German-occupied Poland during World War II. The Nazi political party, also known as the Nationalist Socialist German Workers’ Party, was led by Adolph Hitler.

More than 1.1 million adults and children were murdered at Auschwitz-Birkenau, including almost one million Jewish people. January 27 was designated by the United Nations General Assembly in 2005.