What is the motto of the three musketeers from the famous novel by Alexandre Dumas?

Un pour tous, tous pour un (One for all, and all for one) is a motto traditionally associated with the titular heroes of the novel "The Three Musketeers" written by Alexandre Dumas père, first published in 1844. In the novel, it was the motto of a group of French musketeers named Athos, Porthos, Aramis and d'Artagnan who stayed loyal to each other through thick and thin.

On November 30, 2002, in an elaborate but solemn procession, six Republican Guards carried the coffin of Dumas from its original interment site in the Cimetière de Villers-Cotterêts in Aisne to the Panthéon. The coffin was draped in a blue velvet cloth inscribed with the motto.