10 May 1770,
In the territories of the Spanish State, Carlos III de Borbón ordered the disappearance of all languages other than Spanish. Through the Aranjuez Declaration, they expressed so clearly the persecution of local languages, leaving written their intention to impose languages.
The cedula Carlos III.aren said: “Behin eta berriz, erdaraz bakarrik, dominioetan usatzen den hizkuntza batzuk extingoz.”
Source:
Cédula de Aranjuez.