Nicolas (Colars, Colay) de Douai, active the second half of the thirteenth century, probably belonged to a dynasty of goldsmiths surnamed de Douai, established at Arras and serving the counts of Artois throughout the thirteenth and fourteenth centuries. Although there is some doubt, he has been identified with a monk Nicolas at the abbey of Anchin near Douai, who made a silver gilt retable for the abbey church (completed in 1262; no longer extant). He has also been further identified with "Licuars," whose name is inscribed as artist on the throne of the silver Virgin of the Treasury in the church of Saint-Materne, Walcourt.
Beginning in 1272 and evidently working at Nivelles, Nicolas, his partner Jacques de Nivelles, and their workshop produced a silver châsse to contain the relics of Saint Gertrude at the request of the chapter of the collegiate church of Saint Gertrude in Nivelles. Jacques (Jaquemon, Jakemmon) de Nivelles is otherwise unknown, as is the goldsmith and monk Jacques (Jakenez) d'Anchin, who drew a design for the Nivelles châsse that must have established its iconography. Heraldic evidence on the châsse suggests that some contribution to the expenses for it may have come from Marie of Brabant, who in 1274 married King Philip III the Bold of France. The relics of Saint Gertrude were transferred to the new, completed châsse on 31 May 1298. [This is an edited version of the artist's biography published in the NGA Systematic Catalogue]
Lestocquoy, J. "The Reliquary of St. Gertrude at Nivelles." The Burlington Magazine 77 (1940): 163-164.
Donnay-Rocmans, Claudine. "La châsse de Sainte Gertrude à Nivelles." Gazette des Beaux-Arts 58 (1961): 185-202.
Madou, Mireille. Die Heilige Gertrudis van Nijvel (Verhandelingen van de Koninklijke Academie voor Weten Schappen: Lettern en Schone Kunsten van Belgié.... 2 vols. Brussels, 1975: 1:34-44, 114, 266-267 (no. 143).
Claussen, Peter Cornelius. "Goldschmiede des Mittelalters; Quellen xur Struktur ihrer Werkstatt." Zeitschrift des Deutschen Vereins für Kunstwissenschaft 32 (1978): 46-86, especially 73-78.