Born in Valenciennes, Nord, de Gaulle was struck by a progressive paralyzing illness from his early youth. He turned to scholarship and began a study the Celtic languages after reading Barzaz Breiz (Ballads of Brittany) at the age of sixteen. He learned Breton, Welsh and Gaelic, but never visited a Celtic-speaking country, being confined to his apartment in Paris. Having met Théodore Hersart de la Villemarqué, author of Barzaz Breiz, he became secretary of Breuriez Breiz, a society of Breton poets in Paris. From 1864 he started to publish articles on Celtic culture, especially Brittany, and poetry in the Breton language.

However, as his disease progressed, his publications became increasingly scarce. His literary activity gradually ceased, but he retained until the end his lucidity of mind and was able to follow the progress of his favourite studies. He died at the age of 42.

De Gaulle dreamed of the resurrection of the Celtic languages as vehicles for high culture. A devout Catholic and monarchist, de Gaulle saw Celtic countries as guardians of tradition and proposed a restoration of Breton political autonomy, providing a model for later Breton nationalists. In 1864 he wrote an appeal to the current representatives of the "Celtic race", proposing Celtic festivals:

If I am allowed to express a wish - as yet most ambitious, doubtless difficult to accomplish - it would be to see a new religious order, or at least, a special division of a former religious order, to devote, under the invocation of old saints, wise men from both Britains [The British Isles and Brittany] to preaching and instruction of youth of all classes in the Celtic countries, and this mainly through indigenous languages...After the celebration of holy sacrifice, in open fields, on an old dolmen, surrounded by the people of neighbouring parishes, the solemnities open with a contest of popular bards... Shooting, wrestling, horse and foot races, regattas at the seaside, would provide a new and useful means of improving our agile and robust youth.

De Gaulle insisted that Celtic countries must retain their languages to avoid cultural extinction, asserting that "so long as a conquered people speaks another language than the conquerors, the best part of them is still free". He also proposed a Celtic Union that would establish and develop links between Celtic countries. There should also be a Celtic "esperanto" to facilitate communication and which would be created from common elements in all Celtic languages.

De Gaulle wrote to cultural leaders in Wales, Scotland and Ireland to organise a Pan-Celtic congress in Saint-Brieuc in 1867, which he succeeded in pushing through despite opposition from the French government. Unable to travel, he wrote the poem Da Varsez Breiz (With Bards of Brittany) in Breton, including the lines:

E Paris va c'horf zo dalc'hetMed daved hoc'h nij va speredVel al labous, aden askel,Nij de gaout he vreudeur a bell

(In Paris my body is heldBut towards you my spirit flies,Swftly like a bird,To meet his far away brothers.)

In January 1969, General de Gaulle attempted to use his uncle's reputation in Brittany by declaiming the second quatrain of his uncle's poem Da Varsez Breiz (the lines above) during a speech at Quimper. The speech followed a series of crackdowns on Breton nationalist activists. De Gaulle's use of the poem led to a severe adverse reaction from his audience who drowned out much of the rest of his speech. He was later accused of double standards, having recently spoken in Canada in support of a "free" Quebec, because its French language tradition distinguished it from the English-dominated majority of Canada.