1/2 Tanga - João IV Goa mint to Diu

João IV came to the Portuguese throne in 1640 following the restoration of independence from sixty years of Iberian Union under Spanish rule. The Estado da India's mints were operating in a severely weakened condition by this point — the union period had drained resources eastward into Spanish priorities, and Portuguese Indian coinage had become erratic in both supply and quality. This particular type, struck at Goa for circulation at Diu, reflects the logistical reality of maintaining a scattered network of coastal enclaves dependent on inter-factory bullion transfers rather than local silver supply.

Diu's strategic position at the mouth of the Gulf of Khambhat made small-denomination silver essential for trade, but the roughly three-hundred-kilometer sea route between mints introduced chronic inconsistency in planchet preparation.