Chris, I don't know where you got the idea about castles. There was no castle but again the MacDonalds were more than simple crofters offering hospitality. I wrote the song around 1963, I think, and as already been told, the murders were politically motivated and aslo cotrary to laws of hospitality. The story can be read in John Prebble's book 'Glencoe' whic was published after I wrote my song.