100 000 Réis 1st. print

Pick 78 covers a long issuance window, and the distinction of "1st print" matters here: subsequent printings introduced subtle changes to the plate, making the earliest impressions identifiable to specialists by minor typographic differences in the serial numbering block. At 100,000 Réis, this was the highest denomination in everyday circulation before Portugal's monetary reform replaced the Réis system with the Escudo in 1911 — making notes from the tail end of this series among the last of their kind.

The watermark is the primary authentication tool; forgeries of high-denomination Réis notes were a documented problem in the late nineteenth century, and Banco de Portugal periodically recalled and inspected circulating examples.