For most of their modern history Spain and Portugal have been courteous neighbours, but a historians’ dispute over a key detail of Golden Age history is threatening to tarnish bilateral relations.

The controversy is over which of the countries can claim authorship of the first circumnavigation of the globe in the 16th century.

In 1519, the Portuguese explorer Ferdinand Magellan set off from the Spanish city of Seville, with the aim of opening up a route to the Far East via the Atlantic Ocean. Three years later, the expedition returned having completed the circumnavigation, but under the command of Spanish sailor Juan Sebastián de Elcano.

The disagreement flared up in 2017, when Portugal unveiled its intention to present the “Magellan Route” around the globe as a candidate for Unesco World Heritage status – without crediting Spain. In January of this year, the foreign ministers of the two countries appeared to smooth things over when they agreed that the Unesco application should be shared, as should the 500th-anniversary celebrations of the voyage.

Spanish money

But this month, Spain’s Royal Academy of History has reignited the fracas by publishing a report on the circumnavigation asserting that “the fully and exclusively Spanish nature of the project is not disputable”.

The academy bases its conclusion partly on the financing of the expedition, which was provided by the Spanish crown and local merchants. It also highlights the fact that Magellan embraced Spain because he was unhappy with the royal family of his own country, leading him to Hispanicise his name.

Although Magellan was leader of the expedition, several months into it he had to put down a mutiny by members of his international crew, several of whom he had executed.

Magellan was killed while fighting in the Philippines in 1521 and the relatively unknown Spaniard Elcano took command, leading the expedition back to Spain and glory.

The right-wing newspaper ABC, which has campaigned for Spain’s authorship of the circumnavigation to be acknowledged, welcomed the academy’s report: “Any nation is very conscious of the value of its heroes and their achievements,” it wrote in an editorial in which it blamed Spain’s leftist government for allowing the feat’s national identity to be cast in doubt.

But Portuguese commentators have described the Spanish Royal Academy of History report as a politicised document and they have pointed out that most of its assertions are not new. Historian Francisco Contente Domingues said that “this nationalist reaction is based on a traditional and old-fashioned view of Spanish-Portuguese relations”.

Portuguese columnist Rui Tavares, meanwhile, gave an ironic perspective on the furore in Público newspaper.

“One day we’ll see [Spanish] academics writing to explain why Real Madrid lose so much since Cristiano Ronaldo left,” he noted. “Given that Real Madrid is an ‘exclusively Spanish’ entity, that shouldn’t happen.”