Irish westward as far as the Shannon, while the extent of their power in the direction of the English Pale may be estimated from the fact that the inhabitants of Meath consented to pay them a yearly tribute or black-rent of 300l., and those of Kildare 20l., in order to secure immunity from their attacks. In 1520, when the Earl of Surrey was appointed lord lieutenant, Brian O'Conor was at the height of his power. Being allied to the house of Kildare he was naturally opposed to Henry's project of governing Ireland independently of that noble family, and in June 1521 he joined with O'More and O'Carrol in an attack on the Pale. Surrey at once retaliated by ravaging his territory and capturing his stronghold, Monasteroris. O'Conor for some time refused to listen to peace on any terms, but he eventually submitted, and his castle of Monasteroris was restored to him. On the departure of Surrey things reverted to their old condition. During the detention of Gerald Fitzgerald, ninth earl of Kildare [q. v.], in England in 1528, the vice-deputy, Richard Nugent, seventh baron Delvin [q. v.], made an unwise attempt to withhold from him his customary black-rents out of Meath. O'Conor resented the attempt, and having inveigled the vice-deputy to the borders of Offaly, on pretence of parleying with him, he took him prisoner on 12 May, and flatly refused to surrender him until his demands were conceded. The Earl of Ossory made an unsuccessful effort to procure his release by intriguing with O'Conor's brother Cahir, and Delvin remained a prisoner till early in the following year. In consequence of secret instructions from the Earl of Kildare, who repined at his detention in England, O'Conor in the autumn invaded the Pale, but shortly after the earl's restoration he was pardoned.
When Kildare's son, ‘Silken Thomas’ [see Fitzgerald, Thomas, Lord Offaly, tenth Earl of Kildare], took up arms in 1534 to avenge his father's supposed death, O'Conor was one of his staunchest allies; and it was from O'Conor's castle that he addressed his fatal offer of submission to Lord Leonard Grey. Through the treachery of his brother Cahir, O'Conor was compelled to submit to Skeffington in August 1535, and he gave pledges for the payment of a fine of eight hundred head of cattle. He revenged himself by expelling Cahir from Offaly, but more than a year elapsed without any attempt on his part to redeem his pledges. Accordingly in May 1537 Grey invaded his country, and, having forced him to fly, appointed Cahir lord of Offaly in his stead. For a time O'Conor found shelter with his kinsman O'Carrol; but when O'Carrol was in turn compelled to submit, he came to Grey on a safe-conduct, and promised, if he was restored, not merely to forbear his black-rents, but also ‘to yelde out of his countrie a certen sum yerely to His Grace.’ Grey was unable to grant his request, but he allowed him to redeem his son, who was one of his pledges, for three hundred marks. Though ‘more lyker a begger then he that ever was a captayn or ruler of a contre,’ ‘goyng from on to another of hys olde fryndes to have mete and drynke,’ O'Conor was not subdued. With the assistance of his secret friends he invaded Offaly at the beginning of October ‘with a great number of horsemen, gallowglasses, and kerns,’ and forcibly expelled his brother. Grey at once marched against him, but, in consequence of recent floods, was for some time unable to enter Offaly. In November the rain subsided; but O'Conor had already escaped into O'Doyne's country, and thence into Ely O'Carrol. After destroying an immense quantity of corn and robbing the abbey of Killeigh, Grey returned to Dublin. O'Conor offered to submit, and a safe-conduct was sent him; but he had by that time come to terms with his brother Cahir, and, at his suggestion, retracted his submission. Once more Grey invaded Offaly, but he yielded to O'Conor's solicitation for a parley; and on 2 March 1538 O'Conor made full and complete submission, promising for the future to behave as a loyal subject, to pay a yearly rent of three shillings and fourpence per plowland to the crown, to renounce the pope, and to abstain from levying black-rents in the Pale. Four days later he renewed his submission before the council in Dublin, and preferred a request that he might be created baron of Offaly, that such lands as he possessed ‘per partitionem, more patrie,’ might be confirmed to him and his heirs, and that his brother and other landowners in Offaly might be placed on the same footing. He was pardoned, but his requests were apparently ignored.
For some time he remained quiet, but in 1540 he was implicated in a plot for the restoration by force of Gerald Fitzgerald, the young heir to the earldom of Kildare, and in April and May frequently invaded the Pale. Lord Justice Brereton retaliated by plundering Offaly, but owing to the menacing attitude of O'Donnell and O'Neill, he accepted O'Conor's offer to abide by his indentures, and concluded peace with him. O'Conor's conduct had greatly exasperated Henry, and order was sent for his extirpation, but peace had been concluded before the order arrived; and when St. Leger shortly afterwards assumed the reins of government, O'Conor re-
