County Dublin Tartan Heavyweight 16ozCounty Dublin, or more than likely more accurately, the Dublin Region, is the region that includes the City of Dublin as the capital of Ireland and the biggest city in the entire island of Ireland. Dublin was among the first Counties of Ireland to be formalized, beginning in the 1100s, under the reign of the King John of England. Apart from Dublin, which was the City of Dublin the region is home to the modern counties of Dun Laoghaire, Fingal as well