Tennō
Emperor or King?

Tennō

The Japanese Tennō (天皇 = Heavenly Ruler) is called Emperor outside of Japan. There are voices that consider this designation inappropriate and would rather call the Tennō a king. Whether the tennō is a king or an emperor is perhaps not really important. The question is what function and meaning is ascribed to a king or an emperor.
It is also possible that the term Emperor is less appreciated since Napoleon Bonaparte crowned himself Empereur in 1804 or since the inglorious end of Emperor Maximilian I in Mexico. In European history since Gaius Julius Caesar, an emperor (imperator) always ranked higher than the kings.
But how did it happen that the ruler of Japan was called an emperor?

Originally, the ruler of Japan was referred to as Yamato-ōkimi (Great King of Yamato) or Wakoku-ō (King of Wa). That changed in the 7th century.
Japan came under strong cultural and economic influence from China. In addition to Buddhism and Chinese script, the Chinese nobility and state structures were also adopted.
When the Chinese ruler sent a letter to Japan "From the Son of Heaven", the Japanese responded accordingly. They called their ruler Tennō because they felt they were on the same level as their Chinese counterparts.
It was not until the end of the 7th century that the well-known Japanese chronicles and historical myths were written that claim a descent of the Tennō from the sun goddess Amaterasu. Since then, even the first legendary ruler Jimmu (660 BC) has been retrospectively referred to as Tennō.
After the forced opening of Japan in 1853, the new government also hired advisers from Europe. This led to the fact that the title for the Tennō was set to "Emperor". It was the desire to ascribe to him the rank he deserved in an international comparison.
According to the prevailing view, kings developed from group leaders or tribal leaders, keyword michibiki.
But kings are not a Christian invention, as it is sometimes claimed. So, not calling the ruler of Japan a king, cannot come from the consideration that pagans cannot be kings. However, in the Middle Ages the Church claimed absolute supremacy and so the kings were anointed and crowned in Christian ceremonies.
A fine example of such a coronation can be found in the 2003 film "Johnny English".

Those who don't know the film, might need some background information to understand the coronation scene:
Johnny English (Rowan Atkinson) is a British MI7 agent. He discovered the criminal intentions of French businessman Pascal Sauvage (John Malkovich). Sauvage worked his way up the line of succession to the British throne and recently even forced the Queen to abdicate. He had first planned his coronation with a fake Archbishop of Canterbury.
His business idea is to build numerous privately run prisons on royal land in the kingdom. This plan is stored on a DVD secured by Johnny English. However, he swapped them for a DVD of himself captured by a surveillance camera Sauvage had installed on him.

A coronation ceremony