were then discovered or
completed. One of these highways, the Eiscir Riada, extended from the
declivity on which Dublin Castle now stands, to the peninsula of Marey,
at the head of Galway Bay. It divided Conn's half of Ireland from the
half possessed by Eoghan Mor, with whom he lived in the usual state of
internecine feud which characterized the reigns of this early period.
One of the principal quarrels between these monarchs, was caused by a
complaint which Eoghan made of the shipping arrangements in Dublin.
Conn's half (the northern side) was preferred, and Eoghan demanded a
fair division. They had to decide their claims at the battle of Magh
Lena.[102] Eoghan was assisted by a Spanish chief, whose sister he had
married. But the Iberian and his Celtic brother-in-law were both slain,
and the mounds are still shown which cover their remains.

Conn was succeeded by Conaire II., the father of the three Cairbres, who
were progenitors of important tribes. Cairbre Muse gave his name to six
districts in Munster; the territory of Corcabaiscinn, in Clare, was
named after Cairbre Bascain; and the Dalriada of Antrim were descended
from Cairbre Riada. He is also mentioned by Bede under the name of
Reuda,[103] as the leader of the Scots who came from Hibernia to Alba.
Three centuries later, a fresh colony of Dalriadans laid the foundation
of the Scottish monarchy under Fergus, the son of Erc. Mac Con was the
next Ard-Righ or chief monarch of Ireland. He obtained the royal power
after a battle at Magh Mucruimhe, near Athenry, where Art the
Melancholy, son of Con of the Hundred Battles, and the seven sons of
Oilioll Oluim, were slain.

The reign of Cormac Mac Airt is unquestionably the most celebrated of
all our pagan monarchs. During his early years he had been compelled to
conceal himself among his mother's friends in Connaught; but the severe
rule of the usurper Mac Con excited a desire for his removal, and the
friends of the young prince were not slow to avail themselves of the
popular feeling. He, therefore, appeared unexpectedly at Tara, and
happened to arrive when the monarch was giving judgment in an important
case, which is thus related: Some sheep, the property of a widow,
residing at Tara, had strayed into the queen's private lawn, and eaten
the grass. They were captured, and the case was brought before the king.
He decided that the trespassers should be forfeited; but Cormac
exclaimed that his sentence was unjust, and de