1 Dollar - George III Type I countermark, oval

During the 1790s, a chronic shortage of silver coinage in Britain led the Bank of England to authorize countermarking Spanish colonial eight reales — pieces of eight already circulating informally — rather than strike new coin. The oval countermark bearing the king's portrait was applied at the Bank itself, converting foreign silver into notional British currency at a face value of 4s 9d. The scheme proved short-lived: forgers quickly produced convincing imitations, prompting a wit of the period to quip that the Bank's mark made "the head of a fool to pass for the head of a king."

The Type I oval punch was abandoned by 1797 in favor of an octagonal mark, rendering this earlier variety the scarcer of the two countermark types.