[q. v.], then in exile, the sole survivor of the persons attacked, printed a ‘Vindication’ of himself and friends, dated Paris, 26 Oct. 1731, which was reprinted in London. Other pamphlets, including a ‘Reply’ by Oldmixon and ‘Mr. Oldmixon's Reply … examined,’ followed in 1732, containing vindications of the Earl of Clarendon and of the Stuarts, and charges Oldmixon with himself altering Daniel's ‘History,’ which he had edited for Kennet's ‘Complete History of England’ in 1706. In June 1733 Oldmixon printed and gave away at his house in Southampton Buildings ‘A Reply to the groundless and unjust Reflections upon him in three Weekly Miscellanies’ (Gent. Mag. 1731, p. 514; 1733, pp. 117, 129, 140, 335). It is true that the earlier editions of Clarendon did not give the manuscript in its complete form, but Oldmixon had no sufficient ground for the explicit charges which he made, and passages which he said were interpolations were afterwards found in Lord Clarendon's handwriting (Edinburgh Review, June 1826, pp. 42–6). Dr. Johnson unfairly said (Idler, No. 65) that the authenticity of Clarendon's ‘History’ was brought in question ‘by the two lowest of all human beings—a scribbler for a party and a commissioner of excise,’ i.e. Oldmixon and Duckett. The second volume of Oldmixon's history, ‘The History of England during the Reigns of King William and Queen Mary, Queen Anne, King George I: With a large Vindication of the Author against the groundless Charge of Partiality,’ appeared in 1735; and the third, ‘The History of England during the Reigns of Henry VIII, Edward VI, Queen Mary, Queen Elizabeth,’ in 1739. One main object was to show that our constitution was originally free, and that we do not owe our liberty to the generosity of kings.
In 1730, owing, it is said, to Queen Caroline's interest, Walpole ordered Oldmixon's salary of 100l. at Bridgwater to be doubled, but the money was irregularly paid (Memoirs of the Press, pp. 46, 47), while the promised increase gave rise to a report that Oldmixon was a court writer. Moreover, during the three years which Oldmixon spent in town preparing the second volume of the ‘History’ his deputy involved him in a debt to the crown which after inquiry was reduced to 360l., but Oldmixon was ordered to pay it at once. This he managed to do from the arrears of his allowance of 100l. which the queen directed to be paid him. To ease himself of his troubles, Oldmixon, who was lamed by an attack of gout, soon resigned. In July 1741 he wrote to the Duke of Newcastle in great trouble and distraction. ‘I am now dragged,’ he wrote, ‘to a place I cannot mention, in the midst of all the infirmities of old age, sickness, lameness, and almost blindness, and without the means even of subsisting’ (Add. MS. 32697, f. 308). His last work ‘Memoirs of the Press, Historical and Political, for Thirty Years Past, from 1710 to 1740,’ with a dedication to the Duchess of Marlborough, was not published until immediately after his death (London Magazine, 1742, p. 364). In the postscript Oldmixon asked those who wished to show their concern for his misfortunes to subscribe towards a ‘History of Christianity’ which he had written some years earlier, on the basis of Basnage's ‘Histoire de la Religion des Eglises reformées.’
Oldmixon died on 9 July 1742, aged 69, at his house in Great Pulteney Street, having married in 1703 Elizabeth Parry (the license was granted on 3 March at the faculty office of the Archbishop of Canterbury). He was buried at Ealing on the 12th, near his son and daughter (Lysons, Environs of London,, 1795, ii. 236). Another son, George, died on 15 May 1779, aged 68 (Faulkner, History and Antiquities of Brentford, Ealing, and Chiswick, 1845, p. 194). One daughter, presumably Mrs. Eleanora Marella (Crisp, Somerset Wills, 4th ser. p. 106), sang at Hickford's Rooms in 1746; and another, Hannah Oldmixon of Newland, Gloucestershire, died in 1789, aged 84 (Gent. Mag. 1789, p. 89). A Sir John Oldmixon died in America in 1818; but nothing seems to be known of the title, or whether he was related to the historian (Notes and Queries, 3rd ser. xi. 399, xii. 76).
Besides the books already mentioned, Oldmixon published ‘Court Tales,’ 1717, and a ‘Life’ prefixed to ‘Nixon's Cheshire Prophecy,’ 1719, besides, of course, anonymous pamphlets, translations, &c., which have been forgotten. Of these the ‘History and Life of Robert Blake’ has been already mentioned. His historical work has little value now, as his main object in writing it was to promote the cause of his party. He never hesitated in attacking those on the other side, whether dead or living.