Nippon is the Chinese word for Japan (derived from the Chinese characters which became Japanese Kanji). Nihon is the Japanese word for Japan (which is the way modern Japanese pronounce said characters). Though there are Japanese who still prefer to say Nippon.
The word Japan itself came from Marco Polo, who heard the Chinese read the characters for Nippon literally (Zi-pang, sun origin - which is where the slogan Land of the Rising Sun came from) with a heavy accent. Japan was so widely used by the time it was discovered to be incorrect that it just stuck and even the Japanese government doesn’t care enough to issue a formal correction.
So if I understand correctly, the Chinese pronunciation used to be closer to the Japanese pronunciation of those written characters, but over time the Mandarin pronunciation diverged while the written word stayed the same?
Nippon is the Chinese word for Japan (derived from the Chinese characters which became Japanese Kanji). Nihon is the Japanese word for Japan (which is the way modern Japanese pronounce said characters). Though there are Japanese who still prefer to say Nippon.
The word Japan itself came from Marco Polo, who heard the Chinese read the characters for Nippon literally (Zi-pang, sun origin - which is where the slogan Land of the Rising Sun came from) with a heavy accent. Japan was so widely used by the time it was discovered to be incorrect that it just stuck and even the Japanese government doesn’t care enough to issue a formal correction.
Isn’t the Chinese word for Japan “Rìběn” （日本）?
You can read about the Chinese name for Japan here
https://en.wikipedia.org/wiki/Names_of_Japan
So if I understand correctly, the Chinese pronunciation used to be closer to the Japanese pronunciation of those written characters, but over time the Mandarin pronunciation diverged while the written word stayed the same?