This English expression is not commonly used in day-to-day conversation but can be found in many literary works.
This expression is used in order to denote the act of departing from a situation without either asking for permission or announcing the departure. Generally the phrase is used when someone has left a dinner party or similar social occasion quietly so as not to disrupt the host and the rest of the guests.
The first recorded use of this expression dates to the year 1771 just after the end of the Sevens Years War. It is said to have come into use due to the close relations between Britain and France at the time. The phrase derives from the fact that it was French custom to leave a dinner or ball without first having thanked the host whereas in Britain this was seen as rude and would be looked down upon.
It is also interesting to note the French equivalent of this phrase “filer à l’anglaise” which literally translates as “to escape in the style of the English.”
This expression has been widely used in many famous works of literature.
One such example can be found in Edith Wharton’s 1920 novel The Age of Innocence. The first chapter of this novel contains the following; “look at him — in such hot haste to get married that he took French leave and rushed down to implore the silly girl on his knees!”
Another example can be found in Robert Louis Stevenson’s 1883 novel Treasure Island. The extract reads “but as I was certain I should not be allowed to leave the enclosure, my only plan was to take French leave and slip out when nobody was watching, and that was so bad a way of doing it as made the thing itself wrong. But I was only a boy, and I had made my mind up.”