A manuscript narrating the foundation of Wigmore Abbey records that “Isabella…filia domini de Ferrers de Lechlade” was the second wife of “domini Rogeri”, adding that she became a nun “apud Lechelade” and was buried there. “Rogerus de Mortuomari…et dominæ Isabellæ uxoris meæ” donated property to Kington St Michael by undated charter, witnessed by “Philippo de Mortuomari…”. She inherited Lechlade and Oakham, lost by her older brother when Normandy was conquered by the French in 1204. "Ysabell de Mortuomar" paid a fine for "seisina manerioris de Lichelad et de Langebg q fuerunt Hug de Ferr fratris sui de dono Walkeln patris eorum" in Gloucestershire, dated 1204. The Testa de Nevill lists knights who held land in Gloucestershire, dated to [1211/13]: "Rogerus de Mortuo Mari" held "Lechelad et Langeleg de hereditate uxoris sue".
An order dated [Apr] 1225 delayed repayment from "Peter fitz Herbert and Isabella his wife" of a "debt of Henry de Ferrers brother of the same Isabella". "Dominum Willelmum de Bello Campo, vicecomitem Wygorn et Isabellam uxorem eius" granted "totam terram suam…in Uplodecoumbe" to "dominam Isabellam de Mortuo Mare" by charter dated [24 Jun 1250], witnessed by "…domino Jacobo de Bello Campo…". 1
The estates [of Oakham and Lechlade] escheated to the Crown as a Norman estate when Isabella's eldest brother chose to remain in the lost duchy, but Isabella intervened to purchase the manors at considerable cost from King John.* In contrast to the father, Isabella gave priority to Lechlade over Oakham, clearly preferring the former's proximity to the lands of her husband, Roger de Mortimer, Baron of Wigmore, a marcher lord whose main estates and royal offices were held in Herefordshire and Shrophshire. By the time of her death almost fifty years later, Oakham was worth nearly £11 p.a., but Lechlade drew almost £50 annually, £20 in rents and tolls and £30 from a demesne estate that included two mills, a fishery, a dovecot and a herbage. Isabella's adult life coincided with the span of years that saw the barons of Wigmore, once marginal marcher lords, emerge as some of the most powerful barons in England. On the Gloucestershire border with Oxfordshire, Lechlade was securely within England and on the great road from London to Wales. It thus offered a geographical presence that mirrored the Mortimers' political expansion in these years, beyond the march and into the heart of national politics....
It is only after Roger's death in 1214 that activity began at Lechlade. The barony fell to their son, Hugh, but Isabella retained Oakham and Lechlade, although her tenure was interrupted briefly when the Crown seized both estates in 1219 for default of payment. Married now to Peter fitzHerbert, Isabella used Lechlade to provide for her younger sons, as her father had done before. Initially, her son Roger had held lands in Longborough, part of her Lechlade estate. By 1224 they were in the hands of another son Ralph, who was sued by Hugh for its custody in the king's court. Ralph rebuffed the suit, referring his brother to the rightful defendants in whose name he held the lands: Peter fitzHerbert and Isabella, their mother. Rather than pursue his case against Isabella, Hugh appears to have abandoned his suit. The bridge at Lechlade, now the highest on the Thames, was probably built during these years, and certainly by 1228, when Isabella's use of Lechlade changed abruptly. At this date the manor was held directly by Isabella and Peter and work was suddenly underway, in Peter's name, on a hospital. It is first mentioned in September 1228, when Peter obtained a royal licence to build a gate over the causeway of Lechlade Bridge, in front of the hospital he had built. In 1231 Peter and Isabella secured an archiepiscopal indulgence for the hospital, by 1233 grants of papal protection, liberties and immunities from the bishop, and by 1234 the right for the hospital to hold a five-day fair in the meadow below the bridge. Isabella's work continued apace after Peter's death in 1235, the charters now in her own name. In that year five royal oaks were secured for building at the hospital. She developed the borough, too, establishing a market at Lechlade and securing from the abbot of Cirencester, who held the hundred, jurisdiction over the market in her court there, which included the right to use a pillory and ducking stool. During Peter's lifetime, the couple also claimed judicial privileges, erecting a gallows in Lechlade from which thieves were hung.
Isabella's efforts were shaped by events in her children's lives. She and Roger had had at least five children who survived into adulthood: a daughter, Joan, and sons Hugh,† Roger, Ralph and Philip.... 2
* She secured Lechlade (with Longbridge) in 1205 and Oakham in 1207, each for 300 marks.
† It is possible, although unlikely, that Hugh was Isabella's stepson. The second section of Wigmore Abbey's Fundationis et Fundatorum Historia , written 1399-1401, states that Hugh was the son of a first wife, Milicent de Ferrers, daughter of the earl of Derby. R. W. Eyton's belief that this was a confusion with Milicent, wife of Ralph I, and mother of Hugh I (d. 1149) is reinforced by a 1225 charter of Hugh junioris, in which he conceded four virgates of land to Reading Abbey 'pro salute anime mee et pro animabus Rogeri patris mei et Isabelle matris mee et omnium antecessorum et successorum meorum,' BL, MS Harl. 1708, fol. 56v; Cotton Vespasian Exxv, fol. 241r-v &c.
12 Apr 1225
Order to the barons of the Exchequer to place in respite the demand for 15 marks that they make from Peter fitz Herbert and Isabella, his wife, for the debt of Henry de Ferrers, brother of the same Isabella, until the octaves of Trinity in the ninth year.
Calendar of Fine Rolls, 9 Hen. II, 154
11 Jun 1235
Rex cepit fidelitatem Isabelle que fuit uxor Petri filii Herberti, de omnibus terris et tenementis que ipsam Isabellam hereditarie contingunt et quas predictus Petrus et ipsa Isabella uxor ejus de rege tenuerunt in capite de hereditate ipsius Isabelle. Et mandatum est vicecomiti Glouc' quod de manerio de Lecheland' cum pertinentiis, quod ipsam Isabellam hereditarie contingit et quod ipsi Petrus et Isabella prius tenuerunt, sicut predictum est, eidem Isabelle sine dilatione plenam seisinam habere faciat et ipsam in seisina sua manuteneas et defendas.
Calendar of Close Rolls, 1234-1237, 19 Hen. III, p. 102