Chassant and Sauvage, p. 9. Bishop Ferrocinctus is not mentioned in the medieval catalogues of the bishops of Évreux. Guillaume Bessin (1717). Concilia Rotomagensis provinciae... (in French and Latin). Rouen: Francois Vaultier. p. 373.
Le Noël was the nephew of Jean du Perron, Archbishop of Sens, and of Cardinal Jacques Davy du Perron, whose name he adopted. Auguste Lerosey (1891). Histoire religieuse et civile de Périers et ses notabilités ... (in French). Paris: Berche. pp. 293–296. He took his oath to the King on 24 August 1648. Gauchat, Hierarchia catholica IV, p. 180.
The name of Bishop Ferrocinctus appears, but not the name of his diocese: J.-D. Mansi (ed.), Sacrorum Conciliorum nova et amplissima collectioeditio novissima Tomus IX (Florence 1762), p. 747.