This gentleman, who was educated at Westminster-school under Dr. Busby, was the son of Christopher Jeffrey's, esq; of Weldron in Northamptonshire, and nephew to James lord Chandos. He was admitted of Trinity-college, Cambridge, in 1694, where he took the degrees in arts, was elected fellow in 1701, and presided in the philosophy schools as moderator in 1706. He was also sub-orator for Dr. Ayloffe, and not going into orders within eight years, as the statutes of that college require, he quitted his fellowship in 1709. In the words of one of his contemporaries, (the late vice-master, Dr. Walker,) "he performed his exercises in the college and university with applause; which, with a genteel modest deportment, gained him much esteem." Though Mr. Jeffreys was called to the bar, he never practised the law, but, after acting as secretary to Dr. Hartsonge bishop of Derry, at the latter end of queen Anne's and the beginning of king George the I's reign, spent most of the remainder of his life in the families of the two last dukes of Chandos, his relations. In 1754 he published, by subscription, a 4to volume of miscellanies, in verse and prose, among which are two tragedies, (viz. Edwin and Merope, both acted at the theatre-royal in Lincoln's-inn-fields) and The triumph of truth, an oratorio. All that the compiler of The companion to the playhouse says of Mr. Jeffreys, is, that "he enjoyed some post in the custom-house, and was author of 'one' dramatic piece, which met with little success, entitled Edwin." And Dr. Francklin, the translator of Voltaire's dramatic works, published in 1762, supposes his author "mistaken in asserting, that an English Merope was acted at London in 1731, as, by all the enquiry he (the translator) had made amongst persons concerned in the theatres at that time, he could not discover that any such tragedy was ever exhibited." Yet Quin, Ryan, Milward, &c. acted in it, and the names of Dr. Francklin himself (then Greek professor,) and above twenty other members of Trinity-college, appear in the list of subscribers to Mr. Jeffreys's works. "This collection (as the author observes in his dedication to the present duke of Chandos, then marquess of Carnarvon,) includes an uncommon length of time from the verses on the duke of Gloucester's death in 1700 to those on his lordship's marriage in 1753." Mr. Jeffreys died in 1755, aged 77.