Today is Armistice Day, also known as Remembrance Day.
It is day set aside every year on November 11 to mark the end of World War One.
World War One ended at 11am on the eleventh day of the eleventh month, in 1918. Germany signed an armistice (an agreement for peace and no more fighting) that had been prepared by Britain and France.
This date was declared a national holiday in many nations. In London many people now attend the 11:00 a.m. ceremony at the Cenotaph.
World War One lasted for 4 years.