were routed. In Munster Ruaidrí’s power was also
threatened by the killing of Muirchertach Ua Briain
(his half-brother), but again he dealt easily with the
crisis. He divided the province between Domnall Mór
Ua Briain (d. 1194) and Mac Carthaig before levying
a fine of 720 cows for Muirchertach’s killing. At Athlone
he received the fealty of Mac Gilla Pátraic, and such
was his power that later the kings of Tír nEógain made
their submission there too.
In 1169, Ruaidrí’s confidence in his high kingship
was plain, granting the lector of Armagh ten cows in
perpetuity to lecture Irish and Scottish students in
literature. Alarmingly, Mac Murchada’s second wave
of English troops landed in May, and Diarmait Ua
Máelsechlainn was killed by Domnall Ua Máelsechlainn
(sl. 1173), who established himself as king of east
Mide. Ruaidrí quickly shored up his position, expelling
Domnall, kept west Mide for himself, and gave the
east to Ua Ruairc. But as he plugged one leak, others
appeared. Mac Murchada now attacked the high-king’s
clients in Osraige and West Leinster. A concerned
Ruaidrí summoned the men of Ireland, meeting them
probably at Tara. With Murchad Ua Cearbaill of
Airgialla (d.1189) and Magnus Mac Duinnsléibe of
Ulaid (sl.1171), he went to Dublin to confer with its
ruler before returning to Connacht. To counter Mac
Murchada’s successes in Osraige, Ruaidrí began a cir-
cuit through Munster, Leinster, and Osraige to reas-
sure his allies. With an army of Irish and Ostmen, he
entered Uí Chennselaig to confront Mac Murchada.
AlthoughRuaidrí proved militarily superior, he lost con-
fidence in his ability to impose a military solution.
Characteristically, he changed tactics, opting for politics.
Messengers were dispatched to tempt Robert fitz
Stephen (d. 1210) to desert Mac Murchada. When fitz
Stephen refused, Ruaidrí switched to Mac Murchada
himself, offering an alliance if he would turn on the
English. Mac Murchada turned him down, forcing
Ruaidrí to review his options and dispatch clerics to
treat with the Leinster king. They found him receptive
and struck a deal that confirmed Mac Murchada as
king of Leinster in return for his recognition of
Ruaidrí’s high kingship; the English were to be sent
home; Mac Murchada’s last legitimate son, Conchobar,
was taken by Ruaidrí as a hostage and to him was
promised one of Ruaidrí’s daughters. Satisfied with
these arrangements, Ruaidrí departed.
Matters worsened considerably in 1170. Domnall
Ua Briain revolted against Ruaidrí, distracting the high
king’s attention from Leinster. During the summer,
Ruaidrí’s problems mounted when Mac Murchada
attacked Osraige, Leinster, and Mide and dispatched
English troops to aid Ua Briain. Ruaidrí was forced to
retreat from Thomond and had to content himself with
wasting Ormond. On August 23, Mac Murchada took
Waterford and marched on Dublin. Ruaidrí hastened
to the aid of the Ostmen, positioning his army at
Clondalkin to block Mac Murchada. The Leinster
king, however, cut through the Wicklow mountains to
reach Dublin. The Ostman king, judging that Mac
Murchada had bested Ruaidrí, entered into negotia-
tions with him. Aware of this treachery, Ruaidrí pru-
dently withdrew, leaving the Ostmen to be repaid in
their own faithless coin when the English seized the
city on September 21. Ruaidrí’s withdrawal left Mac
Murchada in complete control of east Leinster and
exposed his clients in west Leinster and Mide to Mac
Murchada’s revenge. The crisis gripping Ruaidrí’s
high kingship was graphically illustrated when Ua
Ruairc forced him to execute Mac Murchada’s hos-
tages for his continued fealty. Ruaidrí and the Irish
kings in general were so alarmed that they may have
dispatched a delegation to Henry II of England seek-
ing protection.
In spite of these terrible reverses, Ruaidrí recovered
in 1171, forcing Ua Briain to submit before mid-year
and was boosted when Mac Murchada died in May.
Ruaidrí now planned a major campaign to support the
Leinstermen fighting the English. With their help and
fleets from the Western Isles and Man, Ruaidrí
besieged Dublin through August and September 1171,
reducing the English to desperate straits. With success
within his grasp, Ruaidrí dictated a peace: the English
could retain the Ostman towns of Dublin, Wexford,
and Waterford, but nothing more. His confidence was
such that he now divided his army. According to the
Irish annals, he left a large contingent at Castleknock
to contain the English at Dublin, and moved off to
rendezvous with his Leinster allies, who were main-
taining the blockade south of the city. He also led an
expedition inland to punish those still loyal to the
family of Diarmait Mac Murchada and the English,
while he dispatched that cavalry of Bréifne and Airgialla
to burn the cornfields of the English near Dublin. The
weakening of the Irish grip around Dublin was
Ruaidrí’s undoing. Twilight was falling as the English
descended on the unprepared camp at Castleknock,
slaughtering hundreds. Ruaidrí’s presence at the rout
is disputed. The Irish sources uniformly say that he
was still away campaigning in Leinster, while the near-
contemporary source known as the Song of Dermot
and the Earl makes no mention of his presence during
the attack. Only Giraldus Cambrensis (Gerald of Wales)
has that Ruaidrí was there; he claimed that Ruaidrí was
having a bath when the English attacked and that he
escaped through the slaughter naked. Be that as it
may, Ruaidrí’s high kingship had suffered an irrevers-
ible shock, forcing him to withdraw from Dublin. On
October 18 Henry II landed at Waterford before pro-
ceeding to Dublin, taking the submissions of Ruaidrí’sUA CONCHOBAIR, RUAIDRÍ (c.1116–1198)