for 150 years the church of Armagh had a bishop as its ruler.
We may suppose that Cellach soon organized the diocese, the limits of
which were fixed at Rathbreasail. But whatever Gilbert or Malchus might
hold as to the source of his authority, we cannot imagine that the
members of the Church in the diocese based their allegiance to him on
any other ground than the fact that he was their abbot and the coarb of
Patrick. That he was a bishop added nothing, in their view, to his
claims. Moreover Cellach belonged to the family which had long supplied
Armagh with abbots. The abuse of hereditary succession had not
disappeared with his appointment.[80] If his successor was chosen in the
time-honoured way, a member of the coarbial family would certainly be
selected, and in all probability he would be a layman, who would not
accept episcopal orders. In a word, all that had been achieved by the
reformers at the most important ecclesiastical centre in Ireland would
be undone.

Cellach had foreseen this, and accordingly he determined to nominate
Malachy as his successor. "With the authority of Patrick" he laid upon
the nobles, and especially upon "the two kings of Munster," the
obligation of securing that his wish should be carried into effect. The
two kings who were thus charged with a difficult duty were Conor
O'Brien, king of Thomond, the principal representative of the O'Briens,
and Cormac MacCarthy, king of Desmond, Malachy's friend.

From Cellach's point of view the choice of a successor which he had made
was a wise one. Malachy was as zealous a reformer as himself. He was a
man of unusual ability and force of character. Besides, he was
possessed of a personal charm which might in time disarm opposition. He
was already a bishop; therefore, if he were once seated in the chair of
Patrick, the question whether the new coarb should be consecrated would
not arise. More important still, he was not of the coarbial stock; with
his entry into the see the scandal of hereditary succession would come
to an end.

But it was not to be expected that the appointment would be accepted
without strong protest; and at the moment there seemed little prospect
that the scheme of Cellach would attain fruition. There is no need to
enter into the details of the fierce struggle that ensued. It is dealt
with elsewhere.[81] Suffice it to say that by 1137, with the aid of
O'Brien and MacCarthy, and apparently with assistance also from Donough
O'Carroll,