bridge, on 21 May 1648, and was elected to a Westminster scholarship there in 1649. He graduated B.A. in January 1651-2, M.A. in 1655, and became fellow of his college on 1 Oct. 1653. He was incorporated B.A. at Oxford on 11 July 1654. On 12 May 1652 he was admitted a student of Gray's Inn. From 1658 to 1660 he was tutor to Jocelyne, son of Algernon, earl of Northumberland. He then went abroad to study physic. His fellowship expired in 1662, and in 1663 he re-entered the earl's family in England (Letters from Lord Percy to Mapletoft are preserved at Alnwick Castle). In 1667 he took his M.D. degree at Cambridge, and was incorporated M.D. at Oxford on 13 July 1669.
While practising in London he made the acquaintance of many of the noted men of the time, both physicians and theologians, and came much into contact with the Cambridge latitudinarians at the house of his kinsman, Thomas Firmin [q. v.] With John Locke, whom he had known at Westminster School, he was for many years on terms of great intimacy. He is said to have introduced him to both Sydenham and Tillotson. With Sydenham Mapletoft was for seven years closely associated in medical practice.
In 1670 he attended Lord Essex in his embassy to Denmark, and in 1672 was in France with the Dowager Duchess of Northumberland. In 1675 he was chosen professor of physic in Gresham College, and in 1676 was again in France with the dowager duchess, then the wife of the Hon. Ralph Montague. He retained his professorship at Gresham College till 10 Oct. 1679, when he retired from medical practice and prepared himself for ordination. He had some scruples about subscribing to the Thirty-nine Articles, and consulted his friend Dr. Simon Patrick [q. v.] (see Dr. Patrick's letter of 8 Feb. 1682-3 in Addit. MS. 5878, f. 151, and in Evanson, Three Discourses, p. 79). But on 3 March 1682-3 he took both deacon's and priest's orders, having previously been presented to the rectory of Braybrooke in Northamptonshire. This living he held until 1685-6, and though non-resident was a benefactor to the place. A letter from Mapletoft, written in 1719, complaining of the misuse of his charity (founded in 1684) and giving some details respecting the parish during his rectorship, is preserved in Braybrooke Church. On 4 Jan. 1684-5 he was chosen lecturer at Ipswich, and on 10 Jan. 1685-6, on his resigning Braybrooke, vicar of St. Lawrence Jewry in London, where he continued to preach till he was over eighty years of age. He also held the lectureship of St. Christopher for a short time from 1685. In 1689-90 he took the degree of D.D. at Cambridge, and henceforth devoted his life to religious and philanthropic objects (cf. Cod. Rawlinson, C. 103).
Mapletoft was an original member of the Company of Adventurers to the Bahamas (4 Sept. 1672), but, being abroad at the time, transferred his share to Locke. In the same year he was using his influence and purse in support of Isaac Barrow's scheme for building a library at Trinity College. He was elected a fellow of the Royal Society on 10 Feb. 1675-6, was member of council in 1677, 1679, 1690, and 1692, and as long as he practised the medical profession took part in the discussions and experiments. He joined the Society for Promoting Christian Knowledge in July 1699, early in the second year of its existence. In this connection he was brought into contact with Robert Nelson [q. v.], with whom he corresponded for some years. He was an original member and active supporter of the Society for the Propagation of the Gospel in Foreign Parts (incorporated by charter in 1701), a benefactor to the library and buildings of Sion College, of which he was president in 1707, and one of the commissioners of Greenwich Hospital.
The last ten years of Mapletoft's life were spent with his daughter, partly in Oxford and partly in Westminster. His mental and bodily health remained excellent till nearly the end (Lansdowne MS. 990, f. 107). He died in Westminster on 10 Nov. 1721, in the ninety-first year of his age, and was buried in the chancel of the church of St. Lawrence Jewry.
On 18 Nov. 1679 Mapletoft married Rebecca, daughter of Lucy Knightley of Hackney, a Hamburg merchant, and younger brother of the Knightleys of Fawsley in Northamptonshire. His wife died on 18 Nov. 1693, the fourteenth anniversary of their wedding-day. By her he had two sons and one daughter: Robert, born in 1684, became fellow of Trinity Hall, Cambridge (LL.B. 1702, LL.D. 1707), advocate of Doctors' Commons (12 July 1707), and commissary of Huntingdon; died on 3 Dec. 1716, and was buried in St. Edward's Church, Cambridge. John, born in 1687, became rector of Broughton in Northamptonshire in 1718, and of Byfield in November 1721, holding both livings till 1753, when he resigned Broughton in favour of his son Nathaniel; he married, on 23 Nov. 1721, Ann, daughter of Richard Walker of Harborough, and died at Byfield on 25 May 1763. Elizabeth, married, 20 Aug. 1703, Francis Gastrell [q. v.], bishop of Chester, and died on 2 Feb. 1761.
