This is the 896th most frequent French word.
allé
"Allé" means "gone" (past participle of "aller," to go).
In this sentence, 'allé' is used as the past participle of 'aller' in the passé composé tense with 'être' as the auxiliary verb to indicate a completed action of going to a location.
Je suis allé au magasin.
I went to the store.
Here, 'allé' is part of the futur antérieur tense to express an action completed in the future relative to another future action.
Il sera allé chez lui avant nous.
He will have gone home before us.
In this question, 'allé' is paired with 'être' in the passé composé to inquire about a past action of traveling to a specific place.