Arms of the Monarchs of Navarre (1349-1425) with the Royal Crest. The Peacock feathers had been adopted by Charles II in 1349.
Ramos Aguirre, Mikel. "Ornamentos paraheráldicos de la Casa Real de Navarra: La cimera".

Anales de la Real Academia Matritense de Heráldica y Genealogía, ISSN 1133-1240, Nº. 3, 1994-1995 , pp. 109-128
Heralder