His visiting espionage, as unkind critics put it—his secret diplomatic mission, as he would have liked to have it put him self—began in the summer of 1722, and he set out for it in company with a certain Madame de Rupelmonde, to whom he as usual made love, taught deism and served as an amusing travelling companion. He stayed at Cambrai for some time, where European diplomatists were still in full session, journeyed to Brussels, went on to The Hague, and then returned. The Henriade had got on considerably during the journey. During the late autumn and winter of 1722-23 he abode chiefly in Paris, taking a kind of lodging in the town house of M. de Bernieres, a nobleman of Rouen, and endeavouring to procure a "privilege" for his poem. In this he was disappointed, but he had the work printed at Rouen nevertheless, and spent the summer of 1723 revising it. In November he caught smallpox and was very seriously ill. The book was privately printed in the spring of 2724. His third tragedy, Mariamne was a failure. The regent had died shortly before, not to Voltaire's advantage ; for he had been a generous patron. Voltaire had made, however, a useful friend in another grand seigneur, as profligate and nearly as intelligent, the duke of Richelieu, and with him he passed 1724 and the next year chiefly, recasting Mariamne (which was now successful), writing the comedy of L'Indiscret, and courting the queen, the ministers, the favourites and all who seemed worth while. The end of 1725 brought a disastrous close to this period of his life. He was insulted by the chevalier de Rohan, replied with his usual sharpness of tongue, and shortly afterwards, when dining with the duke of Sully, was called out and bastinadoed by the cheva lier's hirelings, Rohan himself looking on. Nobody would take his part, and at last, nearly three months after the outrage, he challenged Rohan, who accepted the challenge, but on the morn ing appointed for the duel Voltaire was arrested and sent for the second time to the Bastille. He was kept in confinement a fort night, and was then packed off to England in accordance with his own request. Voltaire revenged himself on the duke of Sully for his conduct towards his guest by cutting Maximilien de Bethune's name out of the Henriade.
Voltaire's visit to England lasted about three years, from 1726 to 1729. George II., who succeeded soon after his arrival, was not fond of "boetry," but Queen Caroline was, and international jeal ousy was pleased at the thought of welcoming a distinguished exile from French illiberality. The Walpoles, Bubb Dodington, Boling broke, Congreve, Sarah, duchess of Marlborough, Pope, were among his English friends. He made acquaintance with, and at least tried to appreciate, Shakespeare. He was much struck by English manners, was deeply penetrated by English toleration for personal freethought and eccentricity, and gained some thou sands of pounds from an authorized English edition of the Henriade, dedicated to the queen. But he visited Paris now and then and gained full licence to return in the spring of 1729.
He was full of literary projects, and immediately after his return he is said to have increased his fortune immensely by a lucky lottery speculation. The Henriade was at last licersed in France ; Brutus, a play which he had printed in England, was accepted for performance, but kept back for a time by the author ; and he began the celebrated poem of the Pucelle, the amusement and the torment of a great part of his life. At the end of 173o Brutus did actually get acted. Then in the spring of the next year he went to Rouen to get Charles XII. surreptitiously printed, which he accomplished. In 1732 another tragedy, Eriphile, ap peared, with the same kind of halting success which had distin guished the appearance of its elder sisters since Oedipe. But at last, on the 13th of August 1732, he produced Zaire, the best (with Merope) of all his plays, and one of the ten or twelve best plays of the whole French classical school. Its motive was borrowed to some extent from Othello, but that matters little. In the following winter the death of the comtesse de Fontaine Martel, whose guest he had been, turned him out of a comfort able abode. He then took lodgings with an agent of his, one Demoulin, in an out-of-the-way part of Paris, and was, for some time at least, as much occupied with contracts, speculation and all sorts of means of gaining money as with literature.
In the middle of this period, however, in 1733, two important books, the Lettres philosophiques sur les Anglais and the Temple du gait appeared. Both were likely to make bad blood, for the latter was, under the mask of easy verse, a satire on con temporary French literature, especially on J. B. Rousseau, and the former was, in the guise of a criticism or rather panegyric of English ways, an attack on everything established in the church and state of France. The book was condemned (June
loth, 1734, the copies seized and burnt, a warrant issued against the author and his dwelling searched. He himself was safe in the independent duchy of Lorraine with Emilie de Breteuil, marquise du Chatelet, with whom he began to be intimate in 1733. The chateau of Cirey, a half-dismantled country house on the borders of Champagne and Lorraine, was fitted up with Voltaire's money and became the headquarters of himself, of his hostess, and now and then of her accommodating husband. Many pictures of the life here, some of them not a little malicious, survive. It was not entirely a bed of roses, for the "respectable Emily's" temper was violent, and after a time she sought lovers who were not so much des cerebraux as Voltaire. But it provided him with a safe and comfortable retreat, and with every oppor tunity for literary work. In March 1735 the ban was formally taken off him, and he was at liberty to return to Paris, a liberty of which he availed himself sparingly.
At Cirey he wrote indefatigably and did not neglect business. The principal literary results of his early years here were the Discours en vers sur l'homme, the play of Alzire and L'Enf ant prodigue (1736), and a long treatise on the Newtonian system which he and Madame du Chatelet wrote together. In the first days of his sojourn he had written a pamphlet with the title of Treatise on Metaphysics. Of metaphysics proper Voltaire neither then nor at any other time understood anything, and the subject, like every other, merely served him as a pretext for laughing at religion with the usual reservation of a tolerably affirmative deism. In March 1736 he received his first letter from Frederick of Prussia, then crown prince only. He was soon again in trouble, this time for the poem of Le Mondain, and he at once crossed the frontier and then made for Brussels. He spent about three months in the Low Countries, and in March 1737 returned to Cirey, and continued writing, making experi ments in physics (he had at this time a large laboratory), and busying himself with iron-founding, the chief industry of the district. The best-known accounts of Cirey life, those of Madame de Grafigny, date from the winter of 1738-39; they are somewhat spiteful but very amusing, depicting the frequent quarrels between Madame du Chatelet and Voltaire, his intense suffering under criticism, his constant dread of the surreptitious publication of the Pucelle (which nevertheless he could not keep his hands from writing or his tongue from reciting to his visitors), and so forth. Frederick, now king of Prussia, made not a few efforts to get Voltaire away from Madame du Chatelet, but unsuccessfully, and the king earned the lady's cordial hatred by persistently refusing or omitting to invite her. At last, in September 174o, master and pupil met for the first time at Cleves, an interview followed three months later by a longer visit. Brussels was again the headquarters in 1741, by which time Voltaire had finished the best and the second or third best of his plays, Merope and Mahomet. Mahomet was played first at Lille in that year ; it did not appear in Paris till August next year, and Merope not till 1743. This last was, and deserved to be, the most successful of its author's whole theatre. During these years much of the Essai sur les moeurs and the Siecle de Louis XIV. was composed. He also returned, not too well-advisedly, to the business of courtier ship, which he had given up since the death of the regent. He was much employed, owing to Richelieu's influence, in the fetes of the dauphin's marriage, and was rewarded, through the influence of Madame de Pompadour on New Year's Day 1745 by the appointment to the post of historiographer-royal, once jointly held by Racine and Boileau. In the same year he wrote a poem on Fontenoy, he received medals from the pope and dedicated Mahomet to him, and he wrote court divertissements and other things to admiration. But Voltaire, who had been for years the first writer in France, had been repeatedly passed over in elections to the Academy. He was at last elected in the spring of 1746, and received on the 9th of May. Then the tide began to turn. His favour at court had naturally exasperated his enemies. He had various proofs of the instability of his hold on the king during 1747 and in 1748. He once lay in hiding for two months with the duchesse du Maine at Sceaux, where were produced the comedietta of La Prude and the tragedy of Rome sauvee, and afterwards for a time lived chiefly at Luneville ; here Madame du Chatelet had established herself at the court of King Stanis laus, and carried on a liaison with Saint-Lambert, an officer in the king's guard. In 1749 she died after the birth of a child.