Mortimer, Roger de, 1st earl of March, 1287?–1330, English nobleman. He inherited (c.1304) the vast estates and the title of his father, Edmund, 7th baron of Wigmore. Appointed lieutenant of Ireland in 1316, he was instrumental in securing the defeat of Edward Bruce and thus was able to consolidate his own holdings in Ireland. His principal estates, however, were in the Welsh Marches, and he joined (1321) the other Marcher lords in opposition to Edward II and the Despensers (see Despenser, Hugh le). He submitted to the king in 1322 and was imprisoned, but in 1323 he escaped to France. When Edward II's queen, Isabella, came to France in 1325, Mortimer became her lover. Together they invaded England in 1326 and routed Edward, whom they forced to abdicate (1327) and later had murdered. Having secured the crown for young Edward III, Mortimer, with Isabella, virtually ruled England and acquired great wealth. He became earl of March in 1328. Finally in 1330 he was seized by Edward III, tried and convicted by Parliament, and executed as a traitor.
See biography by I. Mortimer (2006).
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