March 1719, Voltaire concludes by asking that, if Rousseau wishes to send him a return letter, he do so by addressing it to Monsieur de Voltaire. A postscript explains: "", ("I was so unhappy under the name of Arouet that I have taken another, primarily so as to cease to be confused with the poet Roi.") This probably refers to Adenes le Roi, and the 'oi' diphthong was then pronounced like modern 'ouai', so the similarity to 'Arouet' is clear, and thus, it could well have been part of his rationale. Voltaire is known also to have used at least 178 separate pen names during his lifetime. Career Early fiction Voltaire's next play, Artémire, set in ancient Macedonia, opened on 15 February 1720. It was a flop and only fragments of the text survive. He instead turned to an epic poem about Henry IV of France that he had begun in early 1717. Denied a licence to publish, in August 1722 Voltaire headed north to find a publisher outside France. On the journey, he was accompanied by his mistress, Marie-Marguerite de Rupelmonde, a young widow. At Brussels, Voltaire and Rousseau met up for a few days, before Voltaire and his mistress continued northwards. A publisher was eventually secured in The Hague. In the Netherlands, Voltaire was struck and impressed by the openness and tolerance of Dutch society. On his return to France, he secured a second publisher in Rouen, who agreed to publish La Henriade clandestinely. After Voltaire's recovery from a month-long smallpox infection in November 1723, the first copies were smuggled into Paris and distributed. While the poem was an instant success, Voltaire's new play, Mariamne, was a failure when it first opened in March 1724. Heavily reworked, it opened at the Comédie-Française in April 1725 to a much-improved reception. It was among the entertainments provided at the wedding of Louis XV and Marie Leszczyńska in September 1725. Great Britain In early 1726, the aristocratic chevalier de Rohan-Chabot taunted Voltaire about his change of name, and Voltaire retorted that his name would win the esteem of the world, while Rohan would sully his own. The furious Rohan arranged for his thugs to beat up Voltaire a few days later. Seeking redress, Voltaire challenged Rohan to a duel, but the powerful Rohan family arranged for Voltaire to be arrested and imprisoned without trial in the Bastille on 17 April 1726.