Towards the end of the 11th century, when the tide of Norman invasion swept upwards along the Wye valley, the district became a lordship marcher annexed to that of Brecknock, but was again severed from it on the death of William de Breos, when his daughter Matilda brought it to her husband, Roger Mortimer of Wigmore.
For the next four years Isabella and Mortimer governed in his name, though nominally his guardian was Henry, earl of Lancaster.
Another circumstance was unfavourable to the house of Mortimer - that it derived its title through a woman.
All posts of dignity and emolument were kept for their personal adherents, and a new and formidable dignity was conferred on Mortimer himself, when he was made both justiciar of the principality of Wales, and also earl of March, in which lay both his own broad lands and the estates of Despenser and Arundel, which he had shamelessly appropriated.
He was mixed up with the sordid intrigues which preceded the deposition of Edward II., and supplied Queen Isabella and Mortimer in Paris with money in 1325 from the revenues of Guienne, of which province he was treasurer.
In the summer he defeated the men of Hereford under Edmund Mortimer at Pilleth, near Brynglas, in Radnorshire.
The use made of the names of Mortimer and York, however unauthorized, shows the trend of popular opinion.
The ministers whom Ill, he substituted for the creatures of Mortimer were capable, if not talented administrators.
In the - end the estates of the houses of Lancaster, Kent, Bohun, Burgh and Mortimer swelled the revenues of Edward's children and grandchildren; in whose favour also the new title of duke was introduced.
Immediately after his appointment to Aquitaine, he was sent to France to do homage to his uncle Charles IV., and remained abroad until he accompanied his mother and Mortimer in their expedition to England.