Sibyl de Neufmarché

Sibyl de Neufmarché, Countess of Hereford, suo jure Lady of Brecknock, was a Cambro-Norman noblewoman, heiress to one of the most substantial fiefs in the Welsh Marches. The great-granddaughter of Gruffydd ap Llywelyn, king of Wales, Sibyl was also connected to the nobility of England and Normandy. Sibyl inherited the titles and lands of her father, Bernard de Neufmarché, Lord of Brecon, after her mother, Nest ferch Osbern, had declared her brother Mahel to have been illegitimate. Most of these estates passed to Sibyl's husband, Miles de Gloucester, 1st Earl of Hereford, as her dowry. Their marriage had been arranged personally by King Henry I of England in the spring of 1121. Sibyl, with her extensive lands, was central to the King's plans of consolidating Anglo-Norman power in south-east Wales by the merging of her estates with those of Miles, his loyal subject on whom he relied to implement Crown policy.