St. John’s family traced their lineage to St. Jean, near Rouen in Normandy. In the eleventh century Sir John St. John, one of the Norman conquerors of Glamorgan, was granted Fonmon Castle, the family’s base for three centuries.
When the MP’s father died in 1594 the bulk of his Wiltshire estates descended to his eldest son, Walter; St. John himself acquired Garsington manor, Oxfordshire, and the promise of £200 on reaching his majority. St. John’s guardianship was first entrusted to his distant cousin, the 2nd Baron St. John of Bletso (Sir John St. John II†), and after the latter’s death in 1596 to St. John’s uncle, Sir Oliver St. John, who gave the young man a similar education to his own, at Trinity College, Oxford, and Lincoln’s Inn.
Soon after reaching his majority, St. John was knighted and appointed to the magistracy, the lieutenancy and to a colonelcy of a militia regiment of foot. He may have been less than conscientious in the latter role, for shortly after his appointment the lord lieutenant, Edward Seymour, 1st earl of Hertford, received complaints that St. John’s frequent absences from the county caused the musters in his division to be deferred. In August 1611, somewhat chastened, St. John admitted to Hertford that he was ‘untrained in martial affairs’, but he undertook henceforth to ‘embrace the honouring you with my best service and my country with my greatest ability’.
Although the income from St. John’s estates was substantial - Lydiard Tregoze alone was rated at £30 for the subsidy in 1621 - he was not granted letters of administration for his brother’s estate until November 1611. His purchase of a baronetcy in May 1611 may therefore only have been accomplished by selling Garsington manor.
During the 1610s St. John secured favourable marriages for his numerous sisters, thereby becoming brother-in-law to Giles Mompesson*, Sir Allen Apsley, and Sir Edward Villiers*, half-brother to the future duke of Buckingham. In July 1621 St. John and his stepbrother, Sir Edward Hungerford*, were assigned the £10,000 fine imposed upon Mompesson following the latter’s impeachment, which was almost certainly never collected.
St. John is not known to have sought election for any of the parliamentary boroughs close to Lydiard Tregoze, but in 1624 he paired with Sir Edward Hungerford as knight of the shire. His contribution to the work of the House was negligible: he made no recorded speeches; and the only committee to which he was nominated concerned the estate bill for a Wiltshire gentleman (13 Mar. 1624). As a Wiltshire MP he was also entitled to attend the committee for the butter and cheese bill (3 Apr. 1624).
Proud of his family’s antiquity and lineage, St. John erected numerous monuments to his relatives at Lydiard Tregoze and Battersea and Purley, Surrey.
St. John was a royalist during the Civil War, and while his age may have precluded his own active participation, three of his sons died under arms: William during the assault on Cirencester in February 1643, John after the battle of Newark in December 1643, and Edward in April 1645 of wounds received at the second battle of Newbury. His youngest son, Henry, was sent to the University of Leiden in July 1645, perhaps to avoid a similar fate. However, within a few months of St. John’s death, both Henry and his elder brother Walter married the daughters of the parliamentarian Sir Oliver St. John†, a distant relative. They subsequently fought in the parliamentary army at Worcester in 1651.
In his will of 3 July 1645 St. John repeated, almost verbatim, the religious preamble of his uncle’s will. He bequeathed £1,140 to servants and relatives, and left £10 each to the poor of Battersea and Lydiard Tregoze. His Battersea and Wandsworth properties he had already assigned to his sons Henry and Walter, both of whom were appointed executors, and to Sir Edward Hungerford. The London estates were assigned to provide annuities for his daughters. St. John asked to be buried in the vault in Lydiard Tregoze church, and set aside £200 for his funeral.
St. John’s son Henry was murdered in Ireland in 1665, while Walter, who represented Wootton Basset and Wiltshire in six Parliaments after the Restoration, inherited the St. John estates and baronetcy. St. John’s grandson, Henry†, and great-grandson, also Henry†, were ennobled respectively as Viscount St. John and Viscount Bolingbroke.
