A portrait of King Juan Carlos I is encircled by the country name, the logo of the Royal Spanish Mint (crowned letter M), date and the twelve stars of Europe of whom five are bound by a band.

Juan Carlos I (born 5 January 1938) reigned as King of Spain from 1975 to 2014, when he abdicated in favour of his son, Felipe VI.

In 1969, Francisco Franco, the Spanish dictator chose Juan Carlos, grandson of King Alfonso XIII, to be the next head of state, bypassing his father Juan de Borbón and expecting him to continue Franco's own authoritarian regime. Juan Carlos became King on 22 November 1975, two days after Franco's death, the first reigning monarch since 1931.

Engraver: Luis José Díaz

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.”