Isabella de Fortibus, Countess of Devon

Isabel de Forz (Latinized as Isabella de Fortibus) (July 1237 – 10 November 1293) was the eldest daughter of Baldwin de Redvers, 6th Earl of Devon (1217–1245). On the death of her brother Baldwin de Redvers, 7th Earl of Devon in 1262 without children, she inherited suo jure (in her own right) the earldom and also the feudal barony of Plympton in Devon, and the Lordship of the Isle of Wight. After the early death of her husband and her brother before she was thirty years old, she inherited their estates and became one of the richest women in England, living mainly in Carisbrooke Castle on the Isle of Wight, which she held from the king as tenant-in-chief.

She had six children, all of whom died before her. On her death bed she was persuaded to sell the Isle of Wight to King Edward I, in a transaction that has ever since been considered questionable. Her heir to the feudal barony of Plympton was her cousin Hugh de Courtenay (1276–1340),feudal baron of Okehampton, Devon, who in 1335 was declared Earl of Devon.

Countess Wear, now a suburb of Exeter, is named after a weir that she built on the River Exe, and she is the subject of several legends and traditions.

Isabella was the eldest daughter of Baldwin de Redvers, 6th Earl of Devon (1217–1245) by his wife Amice de Clare (c. 1220 – 1284), daughter of Gilbert de Clare, 5th Earl of Gloucester. Her early life was apparently spent at Tidcombe near Tiverton.

...
Wikipedia