This coin was minted during the time when Brazil was a colony of Portugal. The 6400 Reis was a large denomination coin used primarily for significant transactions and international trade. It reflects the wealth generated in Brazil, much of which was from gold mines, and the importance of Brazilian gold in the global economy of the time.

The obverse of the coin typically features the portrait of the Portuguese monarch. For coins from this period, it would likely be King John V of Portugal.

The reverse side usually displays the royal coat of arms or the kingdom's emblem, symbolizing the monarch's power and the nation's sovereignty.