1/2 Rupee / Deb Period IV

Bhutan's coinage during the early twentieth century was produced under the Deb Raja system, a theocratic administrative structure that ran parallel to — and often in tension with — the emerging authority of the Wangchuck hereditary druk gyalpos. The half rupee designation here reflects Indian monetary influence filtering into the Himalayan kingdom through British trade relationships, though Bhutanese coins of this period circulated largely on local convention rather than any fixed exchange mechanism.

KM#20a is distinguished from related varieties by its copper composition, where earlier strikes used silver or billon. Fabric quality is notoriously inconsistent across the issue's seventeen-year span.