Ok, Basilieus didnt mean king orginally, but a cheiftan or an authority, with wanax being the king or the highest authority
then i went and looked it up and learnt some more
basilieus
"The etymology of "basileus" is unclear. The Mycenaean form was gwasileus (qa-si-re-u),
denoting some sort of court official or local "boss", but not an actual
king. Most linguists assume that it is a non-Greek word that was
adopted by Bronze Age Greeks from a preexisting linguistic substrate of the Eastern Mediterranean. Schindler (1976) argues for an inner-Greek innovation of the -eus inflection type from Indo-European material rather than a "Mediterranean" loan."
"Original senses encountered on clay tablets
The first written instance of this word is found on the baked clay tablets discovered in excavations of Mycenaean palaces originally destroyed by fire. The tablets are dated from the 15th century BC to the 11th century BC. They were inscribed with the Linear B script, which was deciphered by Michael Ventris in 1952 and corresponds to a very early form of Greek.
The word "basileus" is written as "qa-si-re-u" and its original meaning was "chieftain" (in one particular tablet the chieftain of the guild of bronzesmiths is referred to as "qa-si-re-u"). Its meaning later evolved to "king", as is attested in the works of Homer. The word can be contrasted with wanax,
another word used for "king" and usually meaning "High King" or
"overlord". The title "basileus" was used throughout the Greek-speaking
world to signify the person and office of king, either in reality or
when recounting Greek mythology"
Wanax became
anax and
seems to be IE. during the greek dark ages it lost its use from
'basilieus' and was only used in refering to stuff in the past , hero's
and gods. Basilieus went on to be used as the title up until the
end of the East roman empire.