Being commissioned to write the history of the Order of Malta, he sent to a knight for facts concerning the siege of Rhodes: not receiving them, he set about his composition, which he had completed when the documents arrived. He acknowledged their receipt, coolly adding, I am sorry, but my siege is finished (Jen suis fâché, mais mon siège est fait). This became a proverb for work done without the necessary authorities.
The abbé was by turns a Capuchin, a regular canon, a Mathurin, and a member of the Order of Cluny; having written histories of the revolutions of Portugal, Sweden, and Rome, the different offices he held in the Church were called the Revolutions of the Abbé Vertot.