Montesquieu

The prin­ci­ples we have just esta­bli­shed were cruelly vio­la­ted by the Spanish. The Inca Athualpa1 could only be jud­ged by the law of nations ; they jud­ged him by civil and poli­ti­cal laws : they accu­sed him of having had some of his sub­jects put to death, of having had mul­ti­ple wives, etc. And the height of idiocy was that they did not condemn him by the poli­ti­cal and civil laws of his coun­try, but by the poli­ti­cal and civil laws of their own.

See “El Inca,” Garcilaso de la Vega.