A short story written by Charlotte Bronte has been published for the first time after it was discovered at a Belgian museum.

The manuscript, which is entitled L’Ingratitude, was written by the Haworth author for Constantin Heger, a Belgian tutor who taught her and her sister Emily after they travelled to Brussels in 1842 to complete their education. The story, which was last heard of almost a century ago, was found at the Musee Royal de Mariemont and has now been published by the London Review of Books.

During their time in Belgium, the sisters, aged 25 and 23, were asked to compose essays in French – devoirs – in the style of authors they had studied.

L’Ingratitude, the first known devoir of 30 that Charlotte and Emily wrote for Heger, tells the story of a young rat. It is thought to have been based on La Fontaine and J.P. Florian.

The manuscript, which was discovered by archivist and Bronte expert Brian Bracken, was given to Belgian collector Raoul Warocque in 1914 by Heger’s son Paul, the rector of Brussels University.

Andrew McCarthy, director of the Bronte Parsonage museum in Haworth, which has several of the other devoirs, said: “It’s a really interesting discovery and intriguing how it came to be in this museum. It’s something we would be keen to bring to Haworth at some point to display with the other devoirs we have here.

“The discovery ties in with a resurging continental interest in the Brontes.

“Those exercises were quite important in the development of the Brontes as technical writers and would have fed into the great novels they went on to produce.”

The sisters came back to Haworth in November 1842 but in January the following year Charlotte returned alone to become an English teacher and fell deeply in love with Heger, who was understood to have been happily married. After returning to Yorkshire in January 1844, she wrote him a series of letters, four of which were donated to the British Museum in 1913. Charlotte drew upon her experiences in Belgium in her novel Villette, published in 1853.