Who are the Gorosei?

[SSJ2]

What do you think sets these 5 guys above a regular Noble or King of one of the 19 countries?

 

[sei'taer]

Well for starters they seem to be immortal, or at least do not age.

They were probably alive and/or responsible for the void century.

 

[Captain Cadaver]

My guess is they used Bonney's DF ability to keep them in a state away from death, hence why Akainu said he was shocked when he heard she'd fled the Government.