The Royal British Legion is the UK's leading charity providing financial and emotional support to those who have served or are serving in the British armed forces.
It was established in June 1921 and has had a presence in Ireland since the outset.
The symbol of the poppy was inspired by the opening line of the poem In Flanders Fields, which was written by the Canadian physician John McCrae in 1915.
Remembrance Sunday is held on the second Sunday of November, the day closest to the November 11, 1918 Armistice which saw the First World War officially end.
Dublin's St Patrick's Cathedral will host an annual Remembrance Day ceremony tomorrow and President Michael D Higgins will be among those in attendance.