Jehan was born perhaps as early as the 1210s. His family were vassals of the
House of Châtillon for a part of
Louvois. His grandfather, Vauthier, and father, Oudart, were co-ruling their part of Louvois in 1225, when they renounced their half of the viscountcy of
Mailly in exchange for the right to build a
banal oven. Nonetheless, Jehan continued to be known by the vicecomital title, perhaps because it had become attached to their fief in Louvois by then. He had a younger brother named Robert, attested in 1254. Jehan succeeded his father sometime between 1225 and 1252. He held as fiefs of the count the fortress and village of
Dugny and the forests of La Neuville-en-Chaillois, Saint-Basle and Vauremont. He also appears in a list of vassals of Count
Theobald V (1256–1270). Jehan married a daughter of Stephen, lord of
Mareuil-sur-Ay, as attested in a document from the reign of Theobald V. In 1270, he made a donation to the , where he was to be buried, for perpetual masses for his soul. He was by then an old man. The next known lord of Louvois, Bernard (fl. 1286–1295), was possibly his son. ==Poetry==