Depicts the third royal seal (1144) of the first King of Portugal, Dom Afonso Henriques (1106–1185), nicknamed "the Conqueror", encircled by castles and coats of arms facing each of the stars of the European Union. On the upper part of the inner circle appears the word "PORTUGAL", and on the lower part the year of issue.

Engraver: Vítor Manuel Fernandes dos Santos

A geographical map of Western Europe spans the outer ring and inner core on the right side of the coin. The inscription 1 EURO is superimposed over the map of Europe, with the numeral “1” located in an open field representing the eastern Atlantic Ocean.

12 stars are located on the right side of the outer ring, with six stars atop the map of Europe and six stars below it; six vertical stripes cut across the inner core of the coin, visually connecting the upper and lower star segments.

Luc Luycx, a designer at the Royal Belgian Mint, designed the Euro’s common reverse; his initials, LL, are seen on the right side of the design, just under the “O” in “EURO.”