This took place on the 18th of December, 1670. On the 25th of November, 1671, M. de Lauzun was arrested, thrown into the Bastille, and taken thence to Pignerol, where he was subjected to a captivity of ten years. What passed in that interval has proved a great subject of controversy amongst ingenious writers. The most probable explanation seems to be that, notwithstanding the King's refusal, the marriage between Lauzun and Mademoiselle had been accomplished. The evidence of twenty different persons might be cited in support of the fact, but one may suffice. An historian of the last century, M. Anquetil, relates that at the Chateau d'Eu, in 1774, an apartment was still pointed out which had been occupied by Lauzun, situated above that of the princess, and communicating by a secret staircase with her alcove. At the same period, Anquetil saw at Treport a tall person resembling Mademoiselle not only in her figure, but strikingly like her portraits. She seemed to be about seventy or seventy-five. She was called, throughout that part of the country, the Princess's daughter. She seemed to believe so herself, and was in receipt of a pension of fifteen hundred francs paid punctually, without knowing from what quarter they came. She occupied a handsome house for which she paid no rent, although for it she held no proprietary deed. All this, coupled with the age of the lady, who stated that she was born in 1671, would seem decisive as to the clandestine marriage which probably occasioned the arrest of Lauzun.