In violation of the Treaty of Windsor, the lordship of all Connacht, still unconquered, had been granted to William de Burgh. Marriage with De Lacy's heiress had added the lordship of all Ulster, likewise unconquered, and the Earls of Ulster, chiefs of the great house of De Burgh, thus became titular lords of two-fifths of Ireland. To make their dominion a reality was a great incentive to the completion of the conquest. Half a century after the invasion, the conquest extended to about two-thirds of the country. In Leinster, the mountainous parts southward from Dublin were unsubdued; and in the midlands a group of the old Irish states, side by side, had resisted penetration, under the O'Connors of western Offaly, the O'Mores of Leix, the FitzPatricks of Upper Ossory, and the O'Carrolls of Ely. In Munster, MacCarthy More held out in Muskerry and kept the title of king of Desmond. The kings of Thomond preserved more real power, though part of their territory was occupied by the Norman de Clares. In Connacht, the O'Connor kings were still recognised by the Foreigners, and the kings of Breifne were intact. Along the western seaboard, too, the conquest had not taken effect. The De Burghs were established in the fortress of Galway and in the middle plain of Connacht. In the other parts of Leinster and Munster, and all over the old kingdom of Meath, the Irish states had either been altogether subverted or reduced to subjection. In Ulster, the Earls of Ulster held effective dominion over so much territory as is now comprised in the counties of Down and Antrim. The Irish rally may be dated from the year 1241. In that year Maeleachlainn O'Domhnaill became king of Tir Conaill, and by his aid Brian O'Neill became king of Tir Eoghain, defeating in battle the last king of the MagLochlainn line, one who was favourable to the Foreigners and no doubt acknowledged the dominion of the Earl of Ulster. The viceroy, or, as he was then called, justiciar, of the English king as lord of Ireland, was Maurice FitzGerald. He was the most active and enterprising of the new rulers since the first generation of bold adventurers had passed away, and he set himself the task of completing the conquest of Ireland by making the Earl de Burgh effective ruler of his titular lordships of Connacht and Ulster. In Connacht, he succeeded so far as to make the king of Connacht, Feidhlimidh O'Connor, his subject ally, allowing him to retain the title of king. In 1242, FitzGerald took the first step towards the reduction of Ulster by leading an army from Connacht against Tir Conaill and compelling the king, Maeleachlainn O'Domhnaill, to give him hostages. As yet, no fresh occupation of Ulster territory was attempted.