The tricolour green, white and orange flag of the Republic of Ireland was adopted in the Irish constitution in 1937.
The flag’s orange stripe pays respect to the Protestant population of Ireland by representing the ‘Order of the Orange.’ The order is a Northern Ireland-based Protestant-only fraternal organisation that celebrated the ‘Glorious Revolution’ of 1688 where the Protestant Dutchmen William of Orange overthrew King James II of England, a Catholic, and established Protestant ascendancy to the throne and an end to absolute rule. Today the organisation continues to represent Protestant political views and perform marches celebrating Protestant culture and the union with great Britain.
The flag’s green stripe represents revolution and particularly Catholic struggles for civil rights. The ‘Society of the United Irish’ was a group for liberals formed in the 1780’s by elite Protestants who initially wanted a lessening of British influence in Ireland, parliamentary reforms and controversially amongst the group, more rights for Catholics. The group’s symbol was a green flag with a harp in the center, hence the green used in the Republic flag today. The society grew by including the much poorer Catholic population and in 1798 held a rebellion that was brutally crushed because of lack of leadership after British purges and because French aid (France was then enemies with Britain) failed to make it to Ireland.
The colour White is used in the middle of the flag to symbolise a desire for peace between Protestants and Catholics, republicans and unionists.
Despite the original unifying spirit of the flag, it is now seen as representing Catholics and the Republic and is seen as divisive by Protestants and is rarely flown by them.