4 Reales - Charles III

Charles III's 1767 expulsion of the Jesuits from all Spanish territories sent shockwaves through Upper Peru, where the Society had administered vast rural networks closely tied to the mining economy feeding Potosí. The Casa de Moneda itself was mid-transformation during this window — the new neoclassical mint building, begun in 1759, would not be fully operational until 1773, meaning these pieces were struck in a facility simultaneously under construction and under political pressure.

The assayer initial present on any given specimen from this four-year span narrows its date range considerably and remains the primary tool for attribution within the type.