After the partition of Ireland a coat of arms for the new state of Northern Ireland was created and granted a royal warrant in 1924.

The coat of arms uses the de Burgh cross, not St. George, a six pointed star to represent the six counties of Northern Ireland, the British crown, and the red hand of Ulster.

It’s based on the older flag of the province of Ulster which was and still is the de Burgh cross on a yellow background with the red hand in a shield. Interestingly it’s the school crest of Friends School in Lisburn, Northern Ireland which was founded by Quakers.

The flag was derived from the coat of arms, and was used by an old Northern Ireland government. It’s not an official flag (Northern Ireland doesn’t have an official flag) and is exclusively used by the Protestant/Unionist/Loyalist section of Northern Irish society.