Though I think the UK has slightly different rules on who owns antiquities (and of course they differ between the constituent countries of the UK). In England,

Though I think the UK has slightly different rules on who owns antiquities (and of course they differ between the constituent countries of the UK). In England, only certain items (essentially those which have a significant precious metal content, plus prehistoric metal items) are classified as Treasure and belong to the Crown. Other antiquities are by default the property of the landowner to dispose of as they see fit, though metal detectorists and others searching for antiquities usually have an agreement with the landowner about sharing the finds or the proceeds of sale. For instance, the Crosby Garrett Helmet [0] was sold at auction to a private buyer based in the UK for over £2M, which was split between the finder and the landowner. Scotland has a broader definition of treasure that would almost certainly have included the helmet. [0]https://en.wikipedia.org/wiki/Crosby_Garrett_Helmet https://en.wikipedia.org/wiki/Crosby_Garrett_Helmet