The given name Amadeo has its roots in the Late Latin Amadeus, which translates to "love of God". It originated as a Latinized form of the Germanic name Amatheus, derived from the words "amat" (to love) and "Deus" (God).

Amadeo gained popularity during the Middle Ages, particularly in Italy and Spain. In Italy, it was associated with the renowned polymath Amadeus of Portugal, also known as Amadeo VIII, who reigned as King of Portugal from 1433 to 1438. He was a significant figure in the Portuguese Renaissance and a patron of the arts and sciences.

Another notable figure bearing this name was Amadeo Vico, an Italian architect born in 1460, who was famous for his contributions to the Sicilian Renaissance architectural style. His most acclaimed work was the design of the Palazzo Abatellis in Palermo, which showcased his innovative approach to combining Gothic and Renaissance elements.

In the realm of music, Amadeo Amadei (1820-1886) was an Italian composer and violinist from Bologna. He composed several operas, including "La Regina di Scozia" and "Don Gregorio", as well as instrumental works for violin and orchestra.

The name Amadeo also holds significance in Spanish history. Amadeo I, born Ferdinand Maximilian Joseph Maria Amadeus of Savoy-Aosta (1845-1890), was the only King of Spain from the House of Savoy. He reigned briefly from 1870 to 1873 during the turbulent period of the First Spanish Republic.

Another notable bearer of this name was Amadeo Bordiga (1889-1970), an Italian Marxist theorist and a founding member of the Communist Party of Italy. He was a prominent figure in the Italian communist movement and a vocal critic of Stalinism and the Soviet Union.

These examples illustrate the rich history and diverse backgrounds associated with the given name Amadeo, which has been carried by individuals from various walks of life, including royalty, architects, composers, and political thinkers, spanning multiple centuries and cultures.