Killigrew’s father was Sir William Killigrew I’s* elder brother. A distinguished Elizabethan soldier, diplomat and courtier, Sir Henry owned three manors in his native Cornwall, but was based for most of his life in London. He was probably over 60 when, in 1590, he took a Huguenot as his second wife. Killigrew was born in London and baptized there at the French church, but spent part of his childhood in Cornwall, where his father retired.
The proposed marriage was a good match; Elizabeth Hext was sole heir to a prominent Somerset gentry family. However, her father insisted that Killigrew acquire a jointure estate in Somerset near his own lands, and to finance this purchase it was decided to sell or lease two of Killigrew’s Cornish manors. Consequently, in April 1611 the manors were conveyed to new trustees, Killigrew’s kinsmen Sir Henry Neville I* and Sir Maurice Berkeley*, and to Sir Edward Hext himself, but it proved impossible to dispose of them before the marriage went ahead. The purchase of land at Tintinhull, Somerset was finalized in May 1612 only after Killigrew’s family took out loans totalling £7,500. In return for another £2,000 Hext also entailed his manors of Netherham and Somerton on Killigrew and his heirs.
In 1614 Killigrew was elected to Parliament for St. Ives, probably relying primarily on his family’s strong local standing, though the post of duchy havenor, to which he had succeeded after his father’s death, gave him a measure of authority over the port there. His decision to enter the Commons probably sprang from his prominence in the new generation of Killigrews, rather than from his debt problems.
In June 1615, Killigrew obtained possession of the two Cornish manors previously held by trustees, in the hope of facilitating their disposal, but progress remained slow. When he made his will that November, Killigrew was entirely preoccupied with his debts and his lack of a direct male heir. It appears that relations with the Hext family were becoming strained, for though mostly resident at Netherham, where he lived at his father-in-law’s expense, he described himself as ‘of London’ in the will, which is remarkable for making no mention of his wife or infant daughter. Apart from the Hext manors, Killigrew bequeathed his lands to his brother Henry, and appointed his mother and a cousin, Sir Robert Killigrew*, as his executors.