皇 in Chinese / Japanese...

皇 is the simple, single-character way to write emperor in Chinese and Japanese.

皇帝 means emperor in Chinese, Japanese, and old Korean.

From times of old, the emperors of Asia ruled under the authority of God himself. One definition of an emperor is a ruler put in power by God. This definition separates emperors from the various kings in Chinese history (although defining who is a king versus an emperor gets vague sometimes).

Occasionally, the emperor's wife was widowed, and she took the role of an empress until her death (see our entry for empress if that is what you are looking for).

天皇 is the title of the Emperor of Japan.

This title is used in China, Korea, and Japan to refer specifically to the Emperor of Japan.

皇后 is the title of empress/emperess, the female form of the emperor.

皇后 is used in Chinese, Japanese Kanji, and old Korean Hanja.

While the emperor's reign was for life, if he died, his wife would hold his power. In this case, a woman was the ultimate ruler of the greater part of East Asia (now China) until her death and the succession of the emperor's firstborn son to lead the empire. Numerous times in various Chinese dynasties, an empress took power in this way.

The first character means emperor by itself.

The second character alone can mean “wife of an emperor or king” (the first character clarifies that we are talking about an empress and not a queen). It can also mean sovereign or last offspring, depending on context.

Note: In some books, this word is translated as queen. While only incorrect if you get technical (because an empress is theoretically a higher level than a queen), the meaning is very similar.

皇后 is sometimes used for the title of queen, but more technically, this is the wife of the emperor (a higher level than a queen).

天照皇大神 is the title for Sun Goddess or Amaterasu Oomikami in Japanese.

Rare Chinese Buddhists/Shitoists may be familiar with this (so I have included the Chinese pronunciation above) however, this should generally be considered a specifically-Japanese title.

Besides Amaterasuoomikami, this can also be pronounced/romanized as Tenshoukoudaijin. There are several similar ways to write Sun Goddess in Japanese, so don't be surprised if you see different forms on the web, etc.

皇天不负苦心人 is an inspirational Chinese proverb that can be translated in a few ways:

Heaven will not disappoint the person who tries.

If you try hard, you're bound to succeed eventually.

Heaven rewards diligent work.

Sincere/heartful effort reaps the grace of Heaven.