No, it's not trad, or at least not the text. It's a poem, written by a poet named Richard Farina, and set to music by Sandy Denny. The tune is basically trad, being the ssame as or close to My Lagan Love

This is a truly wonderful song. I love to sing it, but I don't find many occasions where it would be appropriate, at least for me in my repertoire.

Dave Oesterreich