Ulster presently contains the counties of Donegal, Derry, Antrim, Tyrone, Down, Fermanagh, Monaghan, Armagh, and Cavan. (Cavan, Monaghan, and Donegal are in the Republic; the rest constitute Northern Ireland.) In ancient times, the extension of Ulster was determined more by the presence of the Ulaid (i.e., the people of Ulster) than any geographical boundaries; this observation applies, of course, to all the geographical divisions of Ireland in ancient times.. Louth, Monaghan, Armagh, and Down were all certainly part of ancient Ulster; as one moves away from this area, the identification becomes more and more vague. The ancient capital was Emuin Machae (var. Emain Macha), which was located near the town of Armagh (approximately two miles west of the town at Navan Fort). The term "capital" does not mean an administrative or legislative center; rather it was the more-or-less permanent site of the royal residence.
Among the legendary persons or groups most prominently associated with Ulster are King Conchubur (var. Conchobar, Conor mac Nessa), Cú Chulaind (var. Cú Chulainn), the important warriors Conall Cernach and Loegaire Buadach, the troublemaker Bricriu Nemthenga (Bricriu of the poisonous tongue, [Dillon 2]), a one-time king of Ulster, Fergus (the name means manly force [Dillon 2]), who resigned in favor of his wife's (Ness) son (Conchobar). Fergus also was a foster father of Cú Chulaind.
Munster (Mumu) contains the present-day counties of Clare, Tipperary, Limerick, Waterford, Kerry, and Cork. In ancient times, it had no clearly defined capital, perhaps because control of the province was not associated with strong dynastic rules as in Ulster.
Some of the legendary persons or groups associated with this province are Fionn mac Cumhal and his Fianna, and King Cormac mac Art (or Aert), an historical figure.
Leinster (Lagin) contains the present-day counties of Louth, Meath, Westmeath, Longford, Dublin, Kildare, Offaly, Laois, Wicklow, Kilkenny, Carlow, and Wexford. In ancient times, like Munster, it had no clearly defined capital and did not include Meath or Westmeath. Leinster also shares the Fionn Cycle with Munster. In Co. Kildare, near Naas, is the Hill of Allen. This large hill protruding above the surrounding bog, legend has it, was the site of the camp of Finn and the Fianna.
Connacht (Connachta) contains the present-day counties of Mayo, Sligo, Leitrim, Roscommon, and Galway. The ancient capital was Crúachu (Crúachan, present day Rathcroghan in Co. Roscommon). A few of the legendary persons or groups associated with this province are King Ailill and Queen Medb, and Findabair (Gwenivere), who was the daughter of Ailill and Medb. Near present-day Sligo Town is Knocknarea (the legendary burial place of Medb), Benbulben, and Drumkill. In the Ulster Cycle, Connacht is the enemy of the Ulaid, but this may obscure the probable historical conflict between Mide under the Uí Néill and Ulaid. Medb is said to be the daughter of the king of Temuir (Gantz 7)
Meath (Mide) seems to have contained what are now the counties of Westmeath and Meath. The ancient capital was Temuir (Tara), and the Uí Néill dynasty is associated with it. In addition to the ancient royal site of Tara, Meath contained the passage graves of New Grange (Bruig na Bóinde), Knowth, and Dowth, which are regarded with awe in the ancient legends concerning the Ulaid and in the Mythological Cycle. The eastern part of Meath is also known as the kingdom of Brega.