Ulster (UK) flag 90 x 150 cm Ulster (Irish: Ulaidh / Cúige Uladh) is one of the four provinces of Ireland, located in the north of the island. Ulster is composed of nine counties: Antrim, Armagh, Down, Fermanagh, Londonderry, and Tyrone comprise Northern Ireland, while Cavan, Donegal, and Monaghan are part of the Republic of Ireland. source: Wikipedia