Dinheiro - João I Lisbon mint

João I secured the Portuguese throne at Aljubarrota in 1385, defeating Castile in one of the more decisive dynastic battles of the Iberian medieval period. The currency reform that followed was partly practical — the preceding years of contested rule between the Aviz and Castilian factions had badly disrupted the coinage — and partly political, with João eager to assert a distinct monetary identity for a kingdom now firmly independent.

At .0833 fine, this dinheiro sits at the lowest end of viable silver coinage; the billon content was not unusual for petty denominations of the period across Iberia.