The biography on the Hymnary page for William Rees was taken from the Dictionary of Welsh Biography, copyright 1959:
https://hymnary.org/person/Rees_William1802
https://biography.wales/article/s-REES-WIL-1802
On the Hymnary page, this is poorly cited and probably should be taken down.
Comments
copyright issue
Yes, thanks for pointing this out. I have removed it.