Edward, prince of Wales, by the old king, Edward I, in person (Worcester Ann. p. 558). Mortimer figured in the coronation of Edward II on 25 Feb. 1308 as a bearer of the royal robes (Fœdera, ii. 36).
Mortimer had inherited from his father a great position in the Welsh marches, besides the lordships of Dunmask and other estates in Ireland. His importance was further increased by his marriage, before October 1306, with Joan de Genville. This lady, who was born on 2 Feb. 1286 (Calendarium Genealigicum, p. 449), was the daughter and heiress of Peter de Genville (d. 1292), by Joan, daughter of Hugh XII of Lusignan and La Marche. One Genville was lord of the castle and town of Ludlow in Shropshire, the marcher liberty of Ewyas Lacy, more to the south, and, as one of the representatives of the Irish branch of the Lacys, lord of the liberty of Trim, which included the moiety of the great Lacy palatinate of Meath (Worcester Ann. p. 560 ; Doyle, ii. 467). Two of his daughters became nuns at Acornbury (Eyton, v. 240), so that their sister brought to Mortimer the whole of her father's estates. The acquisition of Ludlow, subsequently the chief seat of the Mortimers' power, enormously increased their influence on the Welsh border, while the acquisition of half of Meath gave the young Roger a place among the greatest territorial magnates of Ireland. But both his Welsh and Irish estates were in a disturbed condition, and their affairs occupied him so completely for the first few years of Edward II's reign that he had comparatively little leisure for general English politics.
Ireland was Mortimer's first concern. In 1308 he went to that country, and was warmly welcomed by his wife's uncle, Geoffry de Genville, who surrendered all his own estates to him, and entered a house of Dominican friars, where he died (Worcester Ann. p. 560). Yet Mortimer's task was still a very difficult one. Rival families assailed his wife's inheritance, her kinsfolk the Lacys being particularly hostile to the interloper (cf. Cal. Close Rolls, 1307-13, p. 188). Another difficulty arose from Mortimer's claim on Leix, the modern Queen's County, which he inherited from his grandmother, Matilda de Braose (Gilbert, Viceroys of Ireland, p. 136). But his vigour and martial skill at length secured for him the real enjoyment of his Irish possessions, when the Lacys in despair turned to Scotland, and were largely instrumental in inducing Edward Bruce, brother of King Robert, to invade Ireland. In 1316 Mortimer was defeated by Bruce at Kells and driven to Dublin, whence he returned to England. Edward Bruce seemed now likely to become a real king of Ireland, and, to meet the danger, Edward II appointed Mortimer, on 23 Nov. 1316, warden and lieutenant of Ireland, with the very extensive powers necessary to make a good stand against him (Fœdera, ii. 301). All English, lords holding Irish lands were required to serve the new viceroy in person or to contribute a force of soldiers commensurate with the extent of their possessions. In February 1317 a fleet was collected at Haverford west to transport the 'great multitude of soldiers, both horse and foot,' that had been collected to accompany Mortimer to Ireland. On Easter Thursday Mortimer landed at Youghal with a force, it was believed, of fifteen thousand men (Fœdera, ii.. 309; Parl. Writs, ii. i. 484). On his approach Edward Bruce abandoned the south, and retreated to his stronghold of Carrick-fergus, while his brother, King Robert, who had come over to his aid, went back to Scotland. Old feuds stood in the new viceroy's way, especially one with Edmund Butler, yet Mortimer showed great activity in wreaking his vengeance on the remnants of the Bruces' followers in Leinster and Connaught. He procured the liberation of Richard de Burgh, second earl of Ulster [q.v.], whom the citizens of Dublin had imprisoned on account of a private feud. On 3 June 1317 he defeated Walter de Lacy, the real cause of the Scottish invasion, and next day successfully withstood another attack of the beaten, chieftain and his brothers. He then caused the Lacys to be outlawed as 'felons and enemies of the king,' and ordered their estates to be taken into the king's hands (Gilbert, Viceroys, pp. 531-2). This triumph over the rivals of his wife's family for the lordship of Meath was a personal success for Mortimer as well as a political victory. The Lacys fled into Connaught, whither the king's, troops pursued them, winning fresh victories over the Leinster clans, and strengthening the king's party beyond the Shannon. In 1318 Mortimer was recalled to England. He left behind him at Dublin debts to the amount of 1,000l., which he owed for provisions (ib. p. 143). Even before his Irisk command he had been forced to borrow money from the society of the Frescobaldi (Cal. Close Soils, 1307-13, p. 55). Mortimer continued to hold the viceroyalty, being represented during his absence first by William FitzJohn, archbishop of Cashel, and afterwards by Alexander Bicknor [q.v.], archbishop of Dublin. While Bicknor was deputy Edward Bruce was defeated and slain.
In March 1319 Mortimer returned to Ireland, with the additional offices of justiciar
