The tricolour of Ireland was based on that of France and was first used by the nationalists of the Young Ireland movement in 1848, a year of revolution throughout Europe, in their struggle for freedom from Britain. Its colours represent the Catholic, Gaelic and Anglo-Norman communities (green), and the planter group of northern Protestants (orange). The white in the centre signifies a hope of peace and trust between the two. The tricolour in its modern form was recognised by the constitution on December 29, 1937, and was not altered when the Republic of Ireland ended its participation in the British Commonwealth on April 18, 1949.