Why is Mandarin Mandarin?
Mandarin from Oxford University is transliterated by 满大人(mǎn dà rén)—Lord Man because Mandarin Chinese is the official language of feudal nobles in Qing Dynasty. Standard Putonghua is spoken by the Han nationality. While after Manchu gained the power, Putonghua spoken by the ruling class became the so called Mandarin.
Why is it so called Mandarin? Because, in fact, Mandarin has nothing to do with Manchu. To be honest, Mandarin is originated from Portuguese Mandarim. And Mandarim is derivative of mandar which means order and leadership. Early in the Ming Dynasty, the first Europeans made contact with Chinese official were Portuguese. Generally speaking, the Chinese government officials were called Mandarim by them in the year of 1524 for the first time. Therefore, as a title for government officials, Mandarim was created right before Qing Dynasty being established by Manchu.
Later then, English countries changed it into Mandarin. In 1727, the 6th year of Emperor Yongzheng, the British people began to translate the official language of Qing government into Mandarin.
That’s how Mandarin came. Even it has a Man in it, the same pronunciation with 满(mǎn), it wasn’t referring to Manchu, or has no relationship with Qing Dynasty. What a coincidence!