The diocese of Langres honors as saints some martyrs who, according to legend, died in the persecution of Roman Emperor Marcus Aurelius.

They are the triplets Speusippus, Eleusippus, and Melapsippus; Neo, the author of their Acts; Leonilla, their grandmother; and Junilla, their mother.

The diocese was also the birthplace of the theologian Nicolas de Clémenges (fourteenth or fifteenth century), who was canon and treasurer of the Church of Langres; of the Gallican canonist Edmond Richer (1560–1631); of the Jesuit Pierre Lemoine [fr], author of an epic poem on St. Louis and of the work La dévotion aisée (1602–71); and of the philosopher Diderot (1713–84).

The historian Raoul Glaber, monk of Cluny Abbey who died in 1050, was at the priory of St. Léger in this diocese when he experienced an apparition.

Morimond Abbey, the fourth foundation of Cîteaux, was established in 1125 by Odolric, lord of Aigremont, and Simon, Count of Bassigny.

The Augustinian priory of the Val des Écoliers was founded in 1212 at Luzy, near Chaumont, by four doctors of the Paris University who were led into solitude by a love of retreat.

Fifteen mysteries of the life of St. John the Baptist were represented on stages erected throughout the town on the Sunday preceding the "Pardon."

In the Diocese of Langres is Vassy, where, in 1562, riots took place between Catholics and Protestants that gave rise to the wars of religion (see Huguenots).

These held a view to the re-establishment of the synodal organization, and also to impose on the clergy the use of the Roman Breviary (see Prosper Guéranger).