General rule
Copyright lasts for 70 years after the author's death. At the end of this period, the works enter the public domain and can be used without the copyright holders’ permission.
After the author's death, the copyright is owned by his heirs or by the people he appointed for this purpose.
If the author transferred or granted certain rights to specific people, they can continue to exercise those rights after his death. For example, if an employer is the copyright holder of works that were created by his employee, the employer can continue to exploit these works after the death of the employee. The same applies to the publisher or producer to whom an author transferred rights during his lifetime.
Several authors
If a work was created by several authors (collaborative work), the 70-year period starts on the date of death of the longest living author. For example, Asterix was created by René Goscinny (text) and Albert Uderzo (illustrations). Goscinny died on 5 November 1977, whereas Uderzo died in March 2020. This means Asterix will be protected by copyright until 2090, 70 years after Uderzo’s death (and not 2047).
Audiovisual works are collaborative works too. Copyright of such works expires 70 years after the death of the longest living contributor of the following categories: the main director, the screenplay writer, the author of the texts and the author of the musical compositions (with or without lyrics) that were specifically created for the work.
Anonymous works or works under a pseudonym
The copyright of an anonymous or pseudonymous work expires 70 years after the date when the work is legally made available to the public. If the pseudonym adopted by the author leaves no doubt about his identity or if the author made himself known, his work is protected for 70 years after his death.
For example: the Belgian writer Georges Simenon published works under various pseudonyms. Although Georges Simenon died in 1989, the copyright on "L'orgueil d'aimer", which he published in 1926 under the pseudonym of Jean du Perry, will expire in 2059, i.e. 70 years after Georges Simenon's death, and not after the novel's publication, since the real identity of the author is known.