The Muncaster family had been established in Cumberland since the early 13th century, if not before, acquiring over the years the manors of Torpenhow, Hayton, Whitehall, Blennerhasset, Upmanby, Bothland and Bewaldeth, along with land and tenements in Lowcray, Scales, Threapland, Alderscough and ‘Belysis’. Not surprisingly, Sir Robert’s forebears played a fairly prominent part in the local community; and at least three of them, including his grandfather and namesake, represented the county in Parliament.
At first his personal affairs seem to have gone fairly well. In 1392 he conveyed his property in Threapland, Alderscough and Blennerhasset to a group of trustees, including Sir Clement Skelton, Thomas Sands and William Osmundlaw, who were subsequently confirmed in possession by a rival claimant. Only later did he begin to sell off and mortgage more and more of his holdings, clearly as a result of pressing financial problems. The local antiquary who described, in 1623, how ‘Sir Robert ... became an unthrift, and, for very small sums of present money sold his lands to his uncle, Ralph, earl of Westmorland (sic), who, knowing the title to be weak by reason of the entail, did straightaway alien the said lands by parcels, Robert presently after the sale dying’, was obviously mistaken on several points of fact, although there can be little doubt that from 1400 onwards Sir Robert was in urgent need of money, perhaps to pay off a ransom or debts to the Crown. In August of that year he mortgaged all his estates in and around Torpenhow to his kinsman, (Sir) Geoffrey Tilliol, for 250 marks repayable over the next 40 years. Tilliol’s death and the remarriage of his widow, Alice, to (Sir) John Skelton, seems to have placed Sir Robert in such a difficult position that before long he had disposed of a sizeable amount of property in Bewaldeth, and in June 1404 Skelton himself witnessed the sale of his holdings in Lowcray and Scales. By the following January he was under pressure to renegotiate the terms of his mortgage by entering an agreement with Sir William Clifford, who undertook to pay the outstanding 250 marks to Skelton for the use of his young stepdaughter, Katherine Tilliol, in return for a secure title to Torpenhow. Sir William was almost certainly acting as Skelton’s agent, for in June 1406 the latter offered Muncaster a new mortgage of 255 marks repayable over the next 20 years, thus effectively gaining control of the property himself.
Sir Robert’s last years may also have been clouded by political misfortunes, possibly as a result of his involvement in one or more of the insurrections staged by the Percys in the north. At all events, in November 1408, he was pardoned ‘all treason, felonies and trespasses committed by him’, which suggests that he may, in a desperate attempt to avoid financial ruin, have given some support to the rebels. He appears to have died shortly afterwards, since no more is heard of him. According to some sources, he left a daughter, but no contemporary evidence survives about her.