Here is the link to the post with the words of John Ball

Actually that's a mixup, because the song I meant to link to was Sydney Carter's George Fox. Similar, but poor old Father John Ball got executed for his part in the Peasants Revolt, and George Fox died old and respected. And I sang them both in the Hertford Friend's Meeting Houise, and I sometimes get them mixed up.

And here is a link to a thread with George Fox, who was a Friend, unlike John Ball, who was a Catholic priest.