Amadeo I was a prince from the House of Savoy, then king of Spain between 1870 and 1873.

He was born in Turin in 1845. His father was Victor Emmanuel II, and his mother was Archduchess Adelheid Franciska of Austria.

The 1869 constitution changed Spain's form of government. An absolute monarchy became a constitutional monarchy. The biggest concern of the regime change was to find a person who would accept to be the king of Spain at a time when the country was impoverished and the political situation was unstable. In addition, it was necessary to find someone who would accept the constitutional way of governing. Amadé met all the conditions, he came from an ancient family related to the Spanish royal family, he was progressive, Catholic, but a Freemason. He officially accepted his nomination in 1870.

The main concern of his rule was the 10-year war (1868-1878) in Cuba and Puerto Rico, the third war of the Carlists, but mainly the legitimacy of his rule in the eyes of the Spanish, because neither the nobles, nor the liberals, nor the republicans was not recognized. Since he did not feel accepted as a person and was unable to create order in the turbulent political climate despite his good will and a certain degree of political authority, he abdicated in 1873.

In the same year, the first Spanish republic was proclaimed and it did not take long until the Bourbons finally returned to the throne of Spain in the person of Alfonz XII, who was proclaimed king in January 1875.

The reign of King Amadé I in Spain was short, lasting only three years (1870-1873), but during this time significant changes took place in the Spanish coinage. The coins minted by him: Gold: 100 pesetas (1870-1873) Silver: 5 pesetas (1870) -1873), 2 pesetas (1870-1873), 1 peseta (1870-1873), 50 céntimo (1870-1873), 20 céntimo (1870-1873) Copper: 10 céntimo (1870-1873), 5 céntimo (1870- 1873), 1 céntimo (1870-1873) There were mints in these cities: Madrid: 1 peseta (1870-1873), 50 céntimo (1870-1873), 25 céntimo (1870-1873) Barcelona: 1 peseta (1870-1873) , 50 céntimo (1870-1873), 25 céntimo (1870-1873) Seville: 1 peseta (1870-1873), 50 céntimo (1870-1873), 25 céntimo (1870-1873) The coins depicted the portrait of King Amadé I on the obverse and the Spanish coat of arms on the reverse. The fineness of the gold and silver coins was the same as the previous Spanish coins. The weight and size of the copper coins were smaller than the previous Spanish copper coins. The denominations of the mint notes were the same as the coins, but they were made of paper. of Spain issued by I. During the reign of King Amadé, Spain introduced the decimal system in coinage. The 100 pesetas gold coin minted in 1870 is the rarest Spanish coin from the reign of King Amadé I.