Spain's government has refused a demand from Mexico's new president that it apologise for conquering the country five hundred years ago.

Firing the first shots in what threatens to become a diplomatic row, the Left-wing Mexican leader Andrés Manuel López Obrador announced on Monday that he had sent letters to Spain’s King Felipe VI and Pope Francis urging them to apologize for crimes committed against the indigenous peoples of what is today Mexico.

“There were massacres and oppression. The so-called conquest was waged with the sword and the cross. They built their churches on top of the temples,” Mr López Obrador said in a video message.

He filmed the clip at a Mayan monument near the site of the first battle in which Spanish conquistador Hernán Cortés fought indigenous people 500 years ago this month.

Starting from the Tabasco coast and assisted by some indigenous groups who threw in their lot with the invaders, Cortés led a squadron of soldiers eastwards to victory in Tenochtitlan - today’s Mexico City - two years later in 1521. The Aztec empire was destroyed and the indigenous populations were converted to Catholicism.

At a speech to supporters later on Monday, Mr López Obrador said he wanted to reconcile Mexico, the Spanish crown and the Vatican by “together reviewing the history of that military invasion and three centuries of colonisation”.

Mr López Obrador said it was time to bury the Spanish interpretation of the events of 500 years ago as “a meeting of two cultures”, adding that “thousands of indigenous people were murdered”.

Mr Lopez Obrador operates a freewheling presidency with daily press conferences and constant travel around the country, as in his campaign credit: Bloomberg

Hours after the Mexican leader’s message was posted on social media, the Spanish government issued a statement saying it “deeply regretted” that Mr López Obrador had made public the contents of the letter he had sent to Spain’s king – “the contents of which we reject in the most strenuous terms”.

“The arrival of Spaniards in what are now Mexican lands 500 years ago cannot be judged in the light of contemporary thinking. Our peoples have always been able to interpret our shared past without anger and with a constructive perspective,” the Spanish government’s reply read, adding that “there is a great store of affection” between Spaniards and Mexicans.

Historians from both countries were quick to add nuance to Mr López Obrador’s interpretation of the conquest as a battle between evil Spaniards and innocent Mexicans.

“It’s a distortion of historical reality, a manipulation and a political use of history”, Dr Alfredo Ávila from the National Autonomous University of Mexico told the newspaper El País.

“It was a military conquest with all the damage that comes with that, but in the three centuries of subjugation there were times of both cooperation and of resistance,” said Professor Carlos Martínez Shaw of Spain’s history academy.

A month away from a general election, Spanish politicians offered divergent responses. Ione Belarra, a spokeswoman for the Left-wing Podemos, said the Mexican president was right to ask Spain’s king to apologise for the conquest of Mexico, adding that her party is offering the “recovery of democratic and colonial memory that rehabilitates victims”.

But for the leader of Spain’s conservative opposition Popular Party, Pablo Casado, the Mexican demand constitutes “a scandalous degree of ignorance and a genuine offence to Spain and its history”.

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