Henry Fanshawe, baptised 15 August 1569, was the elder son of Thomas Fanshawe (remembrancer of the exchequer) by his first wife, Mary, daughter of Antony Bourchier and was thus a half-brother of Sir Thomas Fanshawe and William Fanshawe. In November 1586 he became a student of the Inner Temple. In 1601, on his father's death, he inherited Ware Park, Hertfordshire, a house in Warwick Lane, London, and a part of St. John's Wood, on condition that he should provide lodging with himself for his stepmother Joan and for his sisters and stepsisters until their marriage.
He succeeded to his father's office as remembrancer of the exchequer. According to the testimony of his daughter-in-law, Anne, wife of Sir Richard Fanshawe, Queen Elizabeth described Henry Fanshawe as "the best officer of accounts she had, and a person of great integrity".
He was elected M.P. for Westbury, Wiltshire, 1 November 1588, and again in February 1592/3. He sat for Boroughbridge, Yorkshire, in the parliament summoned in the autumn of 1597. On 7 May 1603 he was knighted by King James I shortly after his coronation. 
Prince Henry was friendly with him, and had the prince lived he would doubtless have become a secretary of state. He was an enthusiastic student of Italian, and devoted much time to the rearing of horses, which he rode to advantage. Lady Fanshawe reports the course of a negotiation between him and the Earl of Exeter as to the sale of a valuable horse "for a hundred pieces". "His retinue was great, and that made him stretch his estate, which was near if not full £4,000 a year, yet when he died he left no debts upon his estate". Camden is said by Lady Fanshawe to describe Fanshawe's garden at Ware Park as unsurpassed in England for its flowers, physic-herbs, and fruits.
Sir Henry was also a member of the Virginia Company. As such he was one of the noblemen that signed the first and second charters of the new Colony of Virginia. He and his family also received several thousand acres of land as extra compensation for their investments and services. Sir Henry and his heirs, oddly enough, never were recorded as actually visiting their vast estates in the New World.
He died suddenly, at the age of forty-eight, at Ware, early in 1616, and was buried in the church there 12 March. "He was", writes his daughter-in-law, "as handsome and as fine a gentleman as England then had, a most excellent husband, father, friend, and servant to his prince".
Fanshawe had married Elizabeth, daughter of Thomas Smythe of Ostenhanger, Kent, by whom he had six sons: Thomas, Henry (baptised 21 September 1600), Simon (1604-1678), Walter (baptised 1 Sept. 1605), Richard (1608-1666), and Michael (baptised 23 June 1611); besides four daughters: Alice, Mary, Joan (baptised 4 Jan. 1606–7), Anne (baptised 6 Aug. 1609). His widow, who was born in 1577, and whose virtues are highly commended by Anne, lady Fanshawe, her daughter-in-law, survived till 1631, being buried at Ware 3 June.
Sir Henry's will (dated 13 November 1613, and proved April 1616) opens with a long profession of attachment to the Protestant religion, and appoints his widow, her brother Sir Richard Smith, and his eldest son, Thomas, afterwards first Viscount Fanshawe, executors. Among his property mention is made of pictures in oil, prints, drawings, medals, engraved stones, armour, books, and musical instruments, most of which were to be removed from his London house in Warwick Lane to Ware Park, and there to remain for ever as heirlooms. Lady Fanshawe's will, dated 20 February 1629–30, was proved 2 June 1631.
- This article incorporates text from a publication now in the public domain: Lee, Sidney (1889). "Fanshawe, Henry". In Stephen, Leslie. Dictionary of National Biography 18. London: Smith, Elder & Co. pp. 183,184. this source notes the following:
- Genealogical and Historical of the Fanshawe Family, where Sir Henry's funeral certificate and will are printed at length;
- Memoir of Anne, Lady Fanshawe, ed. Nicolas (1829);
- Clutterbuck's Hertfordshire, iii. 294–6;
- Nichols's Progresses of James I;
- Cal. State Papers, Dom. 1600–16;
- Returns of Members of Parliament, i. 425, 431, 436.