 Raised by the midwife Lady Perronette, the twin was taken to the island of Jersey at the age of six, where he was brought up by Marguerite Carteret, daughter of the island's noblest family.Having converted to Catholicism in 1667, he entered the Jesuit novitiate in Rome in April 1668.He then returned to London at the end of 1668 where he is thought to have conspired against Louis XIV alongside a certain Roux de Marcilly, who was denounced and executed in June 1669.