The first verse of the first ode in the first book of odes by Horatius is
Maecenas atavis edite regibus
You Maecenas, who descend from great-great-great-grandfathers that were kings
Who are these atavi (literally great-great-great-grandfathers) Horatius mentions? Does it mean some specific people or ancestry in general?
Maecenas, the Horatius' patron, came from a wealthy equestrian family, but describing such background as kings (reges) sounds tasteless to me — but I may be missing a connotation of the word rex. I was unable to track his ancestry to great-great-great-grandparents, and I'm not sure Horatius could either. Especially since the expression is in plural (atavis regibus rather than atavo rege), I believe it refers to several ancestors in several generations. But it is still possible that Horatius has some specific ancestors in mind instead of his family in general.
Do we know (or have good guesses) what Horatius meant by atavi reges?
This question was partially inspired by this earlier question about generations of grandparents.