Grueso - Juan and Blanca

The grueso was introduced into Navarrese coinage under Juan I (as king of Navarre; he was simultaneously Juan II of Aragon) and his queen Blanca I, whose joint reign was marked by persistent dynastic tension with Castile and the looming succession crisis that would eventually pit their son Carlos de Viana against his own father. Billon issues of this period reflect a treasury under chronic strain — silver content was kept low across most Navarrese minting, and the grueso denomination sat awkwardly between the smaller local coinage and the heavier silver issues that international trade demanded.