Correct tense?

Question

"Avant qu'ils ne partent s'installer là-bas"Why is the subjonctif présent of "partir" used in the above sentence when the sentence refers to the past tense? It was written in English as "Before they went to live over there". Why is it not "Avant qu'ils ne soient partis s'installer là-bas" ? Can someone please enlighten me? Thank you.

Answer

This is a bit tricky and I'm not sure if I can add anything of value.

What occurs to me though is that the opening "avant que" already implies before some event later on.

So "before one goes to live elsewhere" already sets an historic scene. Anything happening after "avant que" has to occupy a place in time after that historic opening scene?

This is why I'm inclined to think that perhaps to put partir in the present works?

That's my input for what it's worth?

Alan (Jim)