I first read The Crow Goddess decades ago, when I was an undergraduate. I must have found it in a second-hand bookshop somewhere – I have no recollection of where – because I’m pretty sure that it was long out of print even then. Still, if you can find a copy, it’s very much worth snapping it up as it’s the best work I’ve read of life in the ancient world of the Celts.
In the Second Branch of the Mabinogi, Brân the Blessed, the giant and King of Britain, is mortally wounded whilst rescuing his sister Branwen from her abusive husband, the King of Ireland. He tells his companions, the seven survivors of that brutal expedition, to cut off his head.