As a Protestant, he was forced into exile in England by the religious conflicts in France during the seventeenth century, where he wrote his History of the Severambians; later translated into French and then a number of other European languages after it found popular success.
(Full Title: The history of the Sevarites or Sevarambi, a nation inhabiting part of the third continent commonly called Terræ australes incognitæ with an account of their admirable government, religion, customs, and language / written by one Captain Siden, a worthy person, who, together with many others, was cast upon those coasts, and lived many years in that country.)
"People which live part of the unintermitting third, commonly called the southern land, containing a relation of the Government, manners, religion & language of this nation, unknown factor until now at the people of Europe", on the assumption of the existence of Southern lands nondiscovered in Indian Ocean in the south-east of Cape of Good Hope.
An innovation of this book, presented in the manner of works of geography or anthropology, was the integration in the romance construction of direct criticism of the revealed and imposed religions, and in particular of the Catholicism of the 17th century.
Initially published in 1675 in London and in English, it then appeared in French in two parts (1677–1679), the first being, according to the author, a kind of "historical journal".