Nigel Tranter 
Druid Sacrifice 

King Arthur’s niece, sister to Gawain and daughter of King Loth, the devoutly Christian Princess Thanea was born to a life of high privilege.But her fortunes took a turn for the worse when she first objected to the druidical practice of human sacrifice and then refused to marry the man her pagan father had picked out for her.Cast adrift in an oarless coracle as a sacrifice to the sea-god, Thanea managed to survive, washed up on the Fife coast and rescued by the monks of St Serf.