King Felipe of Spain appears to have helped thaw frosty relations with Mexico by acknowledging abuses carried out by his country during its conquest.
But in doing so he has reopened a fierce debate over the colonisation of the New World.
The arrival of Spaniards in America from the late 15th Century spread Christianity and the Spanish language across the continent, while also causing the death of many thousands of indigenous people through military action and disease.
During a visit to an exhibition dedicated to indigenous women in Mexico in Madrid's National Archaeological Museum, King Felipe said there had been a lot of abuse during the conquest of the territory that would become Mexico.
There are things that, when we study them, with our present-day criteria, our values, obviously cannot make us feel proud, he added on Monday.
The king made his informal observations as he commented on the exhibition in the presence of the Mexican ambassador to Spain, Quirino Ordaz.
President Claudia Sheinbaum of Mexico has welcomed the comments as a major step forward on an issue that has caused diplomatic friction between the two countries in recent years.
One could say that it is not everything we would have wanted but it is a gesture of reconciliation by the king in terms of what we were talking about: an acknowledgement of excesses, exterminations that happened during the Spaniards' arrival, she said.
The year 2021 marked the 500th anniversary of the fall of Tenochtitlán, the site of modern-day Mexico City and the capital of the Aztec empire, at the hands of Hernán Cortés and his small army.
King Felipe's words mark the first time that a Spanish monarch has publicly acknowledged abuses during the country's colonial era. They were included in a video posted on social media by the Royal Household. Sheinbaum said that the comments should now lead to dialogue on the matter, although it is unclear how that might proceed.
Elma Saiz, a minister in the Socialist-led Spanish government says that the administration endorses the words of [King] Felipe VI 100%. However, the political right was less willing to support the king's remarks.
Alberto Núñez Feijóo, the leader of the conservative People's Party (PP), warned against looking at historical events out of context and emphasized his pride in Spain's legacy in the New World.
The far-right Vox party described the conquest as the greatest work of evangelisation and civilisation in universal history. Vox MEP Hermann Tertsch expressed astonishment at the king's alignment with those questioning Spanish history.
