Burke (de Burgh), Risdeárd (d. 1473), and Burke (de Burgh), Ricard ‘Ó Cuairsge’ (d. 1479), 6th and 7th lords of Lower Connacht (Mayo), and respectively brother and son of Edmund na Féasóige Burke (qv) (d. 1458), 4th lord of Lower Connacht, are an example of an almost shared lordship. After the death of Edmund na Féasóige the lordship passed to his brother Tomás Óg (d. 1460) and then to their brother Risdeárd. However, as Risdeárd was at least 60 years old on his accession in 1460, the real power in the lordship was held by his nephew Ricard, called ‘Ó Cuairsge’, from at latest 1465 on. Ricard Ó Cuairsge played an active role in the politics of the province, attempting to restore his family's control in northern Connacht. In 1466 he intervened in a succession dispute among the O'Connors of Sligo. In 1467 he allied with the O'Kellys and invaded Clanricard but was heavily defeated by Uilleag Ruadh Burke (qv). However, before Uilleag Ruadh could invade Mayo, a peace was forced on him by Aodh Ruadh O'Donnell (qv), lord of Tír Conaill (d. 1505), who was allied with Ricard Ó Cuairsge. The alliance with O'Donnell was shaken by his invasion of Sligo in 1468, but in the next year Ricard, now recognised as the MacWilliam after the abdication of his uncle, joined with O'Donnell in an invasion of Clanricard, which reached as far as Claregalway, destroying that town. The alliance with O'Donnell collapsed in 1470 when Aodh Ruadh captured Sligo castle. Although Ricard recaptured the castle in 1471, his position in northern Connacht was not secure as long as the O'Donnells kept expanding southwards into Sligo. He acted to expand his authority in Connacht, taking hostages at Carbury (1471), and interfering in a dispute among the O'Kellys of Uí Maine (1472), but from 1474 onwards his main theatre of activity was in Sligo against O'Donnell. The two clashed almost yearly in the region of Sligo, especially over the control of Sligo castle. An agreement was reached to divide the region around Sligo in 1476, leaving the castle in O'Donnell's hands, but in 1478 Ricard took back Sligo, gave the castle to the son of Brian O'Connor of Sligo, and devastated O'Donnell's lands in Connacht. This victory kept the O'Donnells from controlling Sligo for several years, but Ricard did not live long enough to follow up on his victory. He died in 1479 in a fall from his horse, and his lordship passed to his cousin Theobald, son of Walter Burke (qv), 3rd lord of Lower Connacht.
Ann. Conn.; H. T. Knox, The history of the county of Mayo (1908): NHI, ix, 171, 172