Killigrew was probably born at Hanworth Park, Middlesex, the residence of his grandfather Sir William Killigrew I*, whose will he witnessed in 1618. Both Sir William and Killigrew’s father, Sir Robert, were notable courtiers who possessed considerable influence in Cornwall, the family’s native county.
In the 1628 parliamentary elections Killigrew was returned for both Penryn, which his father completely dominated, and Newport, where Sir Robert was merely one of several competing local landowners. The ensuing dispute over the five returns made for Newport left Killigrew with at best a chance of securing the second seat there, and on 28 Mar. he opted for Penryn.
At the same time as his initiation into parliamentary politics, Killigrew received his first official employment, as joint captain of Pendennis Castle with his father. He was soon effectively in sole command there, as Sir Robert was appointed vice-chamberlain to the queen shortly afterwards. The castle was intended to protect and supervise Falmouth Harbour, and to begin with Killigrew put on a show of efficiency, reporting on foreign shipping, and promoting the restoration of a lighthouse at the Lizard, in which, admittedly, he had a financial interest.
In April 1633 Killigrew and his father were appointed undertakers for draining the Eight Hundred Fen, south-west of Boston, Lincolnshire. Sir Robert was already involved in another scheme covering the East and West Fens to the north of Boston, and when he died a few months later he bequeathed Killigrew the bulk of his interest there. At about the same time, the first moves were made towards draining a much larger zone directly west of the Eight Hundred Fen, subsequently called Lindsey Level. Killigrew played a key role in all these undertakings, obtaining letters from the king, who stood to gain financially, and securing the support of such leading ministers as secretary of state Sir Francis Windebank† by promising them a share in the lands to be recovered.
The sheer scale of Killigrew’s involvement in the fens forced him to raise capital by disposing of most of his other assets. The sale of Cornish properties inherited from his father brought in £8,000. In addition, the earl of Holland (Henry Rich*) allegedly paid £21,000 for the seal office farm, another part of his patrimony, though Killigrew is unlikely to have received the entire sum as Sir Robert had left the Office encumbered. Despite these measures, by February 1639 Killigrew had fallen behind in his contributions to Lindsey’s works. Indeed, in 1646 he claimed to have spent over £30,000 on draining and to have run up debts of £11,000.
Any prospect that he would soon become solvent was to prove illusory. Aware of the groundswell of opposition in the fens to the drainage projects, Killigrew adopted a characteristically firm response, securing Privy Council judgments against one leading troublemaker, Robert Barkham, and occasionally using force to protect his new enclosures against marauding commoners.
Killigrew’s war service began bravely, when he was given command of the Servants’ Troop, which formed half of the king’s bodyguard. At Edgehill, where Lindsey was killed, Killigrew’s men are said to have attacked a section of the enemy which had been planning to defect, but despite this mishap he received a degree in Oxford a few days later. In July 1643 he helped to arrange the queen’s journey to Oxford, and took part in her grand entry into the town. In the following month he was granted the reversion of the captaincy of Pendennis, now held by John Arundell*, and by the end of the year he was in Cornwall, attempting to rally the local royalists. With the king unable to back his efforts financially, Killigrew found his authority challenged, and in January 1644 he surrendered his title to Pendennis in favour of Arundell’s son.
The next 14 years marked the lowest ebb of Killigrew’s career. Virtually bankrupt, and unable to move about freely for fear of arrest by his creditors, he avoided compounding until 1650. He declared as his sole assets his lost lands in Lincolnshire and personal effects worth £30, but he sold Kempton manor and his manorial rights at Feltham, Middlesex in 1651, and continued to live intermittently at Kempton Park until at least 1653. Thereafter, he seems to have relied on charity. By 1655 he had parted from his wife for financial reasons, though he provoked gossip by continuing to employ a maid in her absence.
Killigrew’s overriding objective was to recover his fenland property. By 1647 he was engaged in a pamphlet war with his opponents, which in 1651 saw him pose improbably as the ally of the poor commoners against wealthy Lincolnshire landowners. With decrees of sewers having failed to guarantee his ownership rights, Killigrew sought parliamentary confirmation of his title. In May 1649 the Rump referred his claims to a committee which sought to arbitrate between the two sides as a prelude to legislation. When the desired compromise proved unattainable, a review of the whole affair was undertaken. Killigrew was apparently not without his supporters; in May 1650 the committee included Carew Ralegh, who had helped to bail him in 1642.
At about this time Killigrew acquired an unlikely ally in the form of Adam Baynes†, an associate of John Lambert†, and a keen property speculator who apparently took an interest in the fenland projects. On 19 Apr. 1653 Killigrew urged Baynes to use his influence in Parliament to revive the stalled Lindsey Level bill, but the legislation was lost when Cromwell ejected the Rump the next day. Although the fens were not a priority for the new Council of State, Cromwell himself favoured a settlement, and in July 1654 a committee of the Council finally recommended that the Lindsey Level undertakers should be restored to their lands. Once again, however, Killigrew and his partners were unable to come to terms with their opponents. He was sufficiently emboldened by developments to try and revive the old Rump bill in the first Protectorate Parliament, and in November 1655 to pursue interim compensation from those occupying his lands, but to no avail. He continued to rely heavily on Baynes, who in April 1655 arranged for him to stay in Lambert’s lodge at Nonsuch, Surrey, and sought his protection in November 1659 when Killigrew’s residence at Lady Strangford’s house in Kent left him open to suspicions of complicity in a recent royalist insurrection.
The prospect of a restored monarchy roused Killigrew to fresh hopes, and he wrote to Charles II in April 1660 reminding him of past services. Shortly after the king’s return he was reinstated as a gentleman usher, and two years later followed in his father’s footsteps by becoming vice-chamberlain to the queen. However, his official income was relatively low, and persistent efforts throughout the 1660s and 1670s to secure legislation on the fens came to nothing, even though he finally returned to the Commons as Member for Richmond in 1664.
