Re: What happenened in yr 27 B.C
Augustus Caesar is crowned first Emperor of Rome. During The yr of 27 B.C.
I suppose this is a metaphore? He was never crowned and was never declared the first Emperor of Rome. He was declared 'imperator', but Ceasar was before him (truly the only reason why he is not considered the first Emperor is that the republic truly but shortly worked between him and following rulers while between following rulers it didn't) and so were many republican leaders including Scipio Africanus. It was always just a title, but given to one that had a true power (imperium=authority, power). August inherited Ceasar's offices including dictator, pontifex maximus (supreme pontiff), 'tribunicia potestas' (to become 'sacrosanctus' as tribunes were), imperator and several others plus privileges not tied to any office. 'Imperator' was not that really important amongst them although it's this word that originated the word 'Emperor'. August 'dropped' all those powers giving them to the senate and they vested in him some of them and created a few new ones including princeps senatus, first of the senate, hence principate. This word actually siginified his function, not 'imperator' that became more important later. He retained the religious office of Pontifex Maximus, was given censor's rights (most notably editing the list of senators), was put in charge of border provinces with the right to choose governors at will and separate treasury (he could levy taxes for that), constitute law with his rescripts (letters), was also made the highest judicial instance. The imperator style (because it practically was only a style) remained with him as well as several other honorary titles including Augustus (elevated by gods, chosen by gods) that later constituted a part of his name and that was again more important than 'imperator'.
As for coronation sensu stricto, it was first performed by St Boniface for Pepin the Short in 751 due to the fact that Pepin, the 'maior domus' and de facto ruler of the Kingdom of Franks needed some legitimation to ascend to the throne. Childeric III was declared unfit to rule and Pepin was anointed and crowned, hence the tradition initially only applying to the kings of Franks. However, intronisation rituals were known and performed in times ancient. The king of Babylon received his insignia from Marduk represented by his archpriest yearly. The essential role is similar, yet it's still not coronation - that is a Christian ritual.