Officially it has no relation to Northern Ireland.
However, a large segment of the Catholic population of Northern Ireland feels a strong affinity to the Republic and some would like to one day see the whole island governed from Dublin.
In areas where such sentiments predominate, you are likely to see the Tricolor flying.
The flag was first introduced by Thomas Meagher in 1848. Meagher was an Irish nationalist. He later moved to America where he served as a general in the Civil War and eventually as a politician.
He brought the design of the Irish flag back from France where he had gone to study revolutionary movements. The original design had the orange next to the flag staff and also had the red hand of Ulster in the white column.
The flag was officially adopted in 1919.
Symbolism of the Irish Flag
The flag consists of a green, a white and an orange vertical columns.
The green symbolizes the Catholic majority;
the orange symbolizes the Protestants.
The white in between represents a lasting peace that has often eluded the two communities.
Now that you know all about this flag, why don't you read about the other unofficial flags of Northern Ireland?