se había marchado

had left

→ se
phrase Rare #46,014
had left The past perfect form of marcharse, used to say that someone had already left or gone away before another past event. The pronoun se is part of the verb marcharse.
SP: Cuando llegué a casa, mi hermana ya se había marchado.
EN: When I got home, my sister had already left.

Pensé que Tom se había marchado con María.

I thought Tom had left with Maria.

Su padre real, que se había marchado antes de que él naciera.

His real father, who had left before he was born.

— It's Such a Beautiful Day (2012)

Os conté que se había marchado a Barcelona.

I told you all that he had gone to Barcelona.

Llegando a la estación, encontré a mi tren que se había marchado.

Arriving at the station, I found my train had already left.