As Harvey IV was still a minor when his father died, the Lordship of Léon was ruled directly by the Duke of Brittany, John I the Red.

Herve seems to have lived in France, where he married Maud of Poissy,[1] daughter and heiress of William of Poissy and his wife Isabella of Marly, and used the title Lord of Châteauneuf, which he had inherited from his mother Margaret of Châteauneuf, until 1260.

In September 1281, he gave all his properties in Châteauneuf and Senonches to King Philip III the Bold.

This part of Herve’s inheritance then passed to Louis of Valois, Count of Chartres and Alençon (younger son of Charles I, Count of Valois, Alençon and Perche; brother of Philip IV the Fair), who was granted Châteauneuf-en-Thymerais.

Louis died without issue in 1328/29 and King Philip VI gave a part of Louis’ inheritance to his younger son Charles II of Valois, Count of Alençon and Perche, granting him Châteauneuf-en-Thimerais and Senonches, as well as Champrond, among other lands, in a charter dated May 1335.