It is a song from a well-known 19th century opera, The Bohemian Girl by Balfe (shows up memorably in James Joyce's story, Clay in Dubliners):

I dreamt that I dwelt in marble halls,
With vassals and serfs at my side,
And of all who assembled within those walls,
That I was the hope and the pride.
I had riches too great to count, could boast
Of a high ancestral name;
But I also dreamt, which pleased me most,
That you loved me still the same.

I dreamt that suitors sought my hand,
That knights upon bended knee,
And with vows no maiden heart could withstand,
They pledged their faith to me.
And I dreamt that one of that noble host
Came forth my hand to claim;
But I also dreamt, which charmed me most,
That you loved me still the same.