25 Dirhams

The Qatar and Dubai Currency Board was a short-lived monetary authority established in 1966 after the Gulf rupee — issued by India — was abruptly withdrawn following India's devaluation. Qatar and Dubai briefly shared a currency before Dubai joined the UAE dirham system in 1971 and Qatar launched its own riyal. This coin exists precisely because two politically distinct sheikhdoms needed a stopgap solution fast.

The arrangement lasted barely five years.