As a result of the conquest, mining extractive processes in the southwest of the peninsula (which required a massive number of forced laborers, initially from Hispania and latter also from the Gallic borderlands and other locations of the Mediterranean), increased by leaps and bounds, bringing the interaction of slaving and ecocide, entailing far-reaching environmental outcome in terms of pollution records, unmatched in the Mediterranean region until the Industrial Revolution.

The Rome-based Latin Church would go on to hold nonetheless substantial clout over Christian polities of the Peninsula for the rest of the middle ages.

Despite some incipient attempts to promote further understanding between the two countries, immediately after the end of World War I, there were still issues restraining further Italian-Spanish engagement in Spain.

This includes a sector of public opinion showing aversion towards Italy; a prominent example being Austria-born Queen Mother Maria Christina.

While showing a will for friendship and rapprochement, the "Treaty for Conciliation and Arbitration" signed in August 1926 between the two countries delivered limited substance in practical terms, compared to the expectations at the starting point of the Primorriverista dictatorship.

Between 1938 and 1939, according to the historian Rodrigo Javier, "the Italians were crucial to the success of the Rebel army...in breaking through and stabilizing the Aragon front, in the occupation of Barcelona and Girona and in concluding the Levantine campaign".

[25] However, after the Italian-American armistice had been made public, the Spanish papers extensively quoted the official German statement, which lambasted the Italian treason.

[35] Starting in the 1960s, Franco also provided support to Ordine Nuovo and National Vanguard, also lending sanctuary to putschist Junio Valerio Borghese in 1970, with Spain henceforth serving as a den for some Italian far-right terrorists, who eventually played themselves a role in the so-called Spanish Transition.

[38] Both governments outlined plans for the empowerment of a Madrid-Rome axis vis-à-vis EU negotiations of post COVID-19 reconstruction during the second cabinet of Italian prime minister Giuseppe Conte, with Pedro Sánchez as his Spanish counterpart.

[39] The arrival of Mario Draghi to Italian premiership, however, further distanced the position between both countries, contrasting to the hitherto "relative alignment" cultivated by Conte.

[40] In November 2021, Italian President Sergio Mattarella made a state visit to Spain, and was received by King Felipe VI at the Royal Palace of Madrid.

Spanish foreign minister Albares proposed to his Italian counterpart Di Maio the "relaunch" of the relationship between the parliaments of Spain and Italy and raised the prospect of creating an investment forum between companies from both countries pertaining to projects making use of EU funds.

[42][43] In November, the Italian Prime Minister, Giorgia Meloni, stated that cooperation on energy, "real economy" and immigration will continue, strengthening bilateral relations within the common framework of the EU and NATO.