Until 1945, Remembrance Sunday was known
as ARMISTICE DAY.
Since 1956, Sunday has been the day of commemoration. In the United Kingdom, Remembrance Sunday is the national day of remembrance for all those who were killed in WW1 and WW2 and later conflicts and ceremonies take place on the second Sunday of November.
There is a 2-minute silence at 11 a.m. (the signature of the armistice with Germany had taken place at 11 a.m. on 11th November 1918).The ceremonies take place at the Cenotaph in London (and elsewhere) in the presence of H.M. Queen Elizabeth II and all the members of the Royal Family and representatives from all Commonwealth countries.
The poppies (Flanders fields in Belgium) symbolise the blood shed by those who were killed and are sold (by the British Legion) in aid of the war invalids (ex-servicemen) and members of their families.
Sources: The Brewer's Dictionary of Phrase and Fable and The Hutchinson Encyclopaedia
LONDON (November 11th, 1918)
"In Victoria Street a group of Australian 'boys' accompanied by a band and their girls decorated in red, white and blue were swinging down towards Whitehall to the huge delight of all spectators. (...) In Whitehall we got blocked, but what did it matter? We danced on the 'buses, we danced on the lorries, we danced on the pavement, we shouted, we sang. (...) the office boys and girls at the War Office yelled to their companions across the way; we cheered and cheered again and again, while the Church bells rang out a peal of jubilation..."
Source: Sir Evelyn Wrench, Struggle, 1914-1920 in THEY SAW IT HAPPEN - 1897-1940 , Compiled by ASA BRIGGS.
"It was a few minutes before the eleventh hour of the eleventh day of the eleventh month. I stood at the window of my room looking up Northumberland Avenue towards Trafalgar Square, waiting for Big Ben to tell that the War was over. My mind strayed back across the scarring years to the scene and emotions of the night at the Admiralty when I listened for these same chimes in order to give the signal of war against Germany to our Fleets and squadrons across the world. And now all was over! The unarmed and untrained island nation, who with no defence but its Navy had faced unquestioningly the strongest manifestation of military power in human record, had completed its task. (...) An then suddenly the first stroke of the chime. I looked again at the broad street beneath me. It was deserted. From the portals of one of the large hotels absorbed by Government Departments darted the slight figure of a girl clerk, distractedly gesticulating while another stroke resounded. Then from all sides men and women came scurrying into the street.Streams of people poured out of all the buildings. The bells of London began to clash. (...) Flags appeared as if by magic. (...) men and women (...) mingled with torrents pouring down the Strand on their way to acclaim the King. (...) Safety, freedom, peace, home, the dear one back at the fireside -- all after fifty-two months of gaunt distortion."
Between the crosses, row on row,
That mark our place; and in the sky
The larks, still bravely singing, fly
Scarce heard amid the guns below.
We are Dead. Short days ago
We lived, felt down, saw sunset glow,
Loved, and were loved, and now we lie
In Flanders fields.
Take up your quarrel with the foe;
To you from falling hands we throw
The torch; be yours to hold it high.
If ye break faith with us who die
We shall not sleep, though poppies grow
In Flanders fields.
(written by Liet.-Col. John McCrae, a Canadian serving at Ypres)