Onluk - Mahmud I Kostantiniyye mint

The onluk was struck in the opening months of Mahmud I's reign, which began under the worst possible circumstances: his predecessor Ahmed III had just been deposed in the Patrona Halil rebellion of September 1730, a janissary-led uprising that forced the abdication after years of resentment toward court extravagance during the Tulip Period. Mahmud came to power as a compromise figure and had Patrona Halil himself executed within weeks — a swift consolidation that stabilized the throne but left the treasury in disorder.

The billon standard at roughly 46.5% fineness reflects ongoing Ottoman silver debasement that had accelerated through the early eighteenth century, with the Kostantiniyye mint bearing the heaviest production burden of any imperial facility.