Prideaux belonged to an ancient West Country family with a pedigree stretching back to the Conquest and a parliamentary record dating from 1298. In 1603 his father Richard inherited five Devon manors, including Thuborough, and sufficient property in Cornwall to qualify him as a j.p. there.
Prideaux finally came to terms with Arundell in 1622, but by then he was embroiled in a dispute with his stepmother. Richard’s will of 1614 had observed that the loss of so many properties had undermined his ability to provide for his family, and his widow Zenobia subsequently sought to augment the legacies designated for her daughters. In 1621 a reluctant Prideaux agreed to find an additional £200, mortgaging a manor to Zenobia as security for payment, but he then missed the vital deadline. His stepmother foreclosed on the mortgage, a Chancery suit again ensued, and although in November 1624 Prideaux’s right to the manor was confirmed on condition that he paid a revised settlement to his half-sisters, he still failed to produce the money. The situation was further complicated by the fact that, since 1622, he had been outlawed over other outstanding debts.
On 6 May 1625 Prideaux was elected to Parliament at Bossiney, doubtless through the influence of a junior branch of his family which possessed property in the area.
In 1629, in urgent need of £1,000, Prideaux sold his largest remaining Arundell manor to Lord Mohun (John Mohun*). However, his subsequent claim that he had been coerced into an outright sale when seeking only a mortgage may have been accepted by Chancery, since the property seems to have continued in his family until 1704.
