President of the Holocaust Memorial Day Trust and survivor Ben Helfgott today lit a candle in memory of the Holocaust's victims at the Millennium Bridge in central London.
The theme this year was "build a bridge", with people asked to build symbolic bridges between communities so atrocities such as the Holocaust are never repeated.
Mr Helfgott said the event was a "reminder of what happened and why it happened".
The 83-year-old lost his parents, his youngest sister and many people from his extended family in the Holocaust.
He spent a total of five years, eight months and five days in ghettos, labour and concentration camps.
Ben Helfgott on why today's event is so important.