Jonathan Thomas looks at some of the surprising links between slave-owners and churches in Wales - links that can turn up in some unexpected places. A gold communion cup in Welshpool; a secret Baptist meeting place near Swansea, run by a man who would go on to own slaves in New England; and a farmhouse near Talgarth that was once a college for Methodist ministers are just three examples around Wales that cast light on this inglorious chapter in Welsh history.