The story is that the crane bag, also known as the Treasure Bag of the Fianna, was made by Manannan from Aoife's skin after she died in which he kept all of his treasures. It is speculated that the bag had shamanic uses. According to Ellis, Aoife was the lover of Manannan's son Ilbrec. She was changed into a crane and while in this form was killed. "The bag contained numerous articles with magical properties, such as the knife and shirt of Mananna/n Mac Lir." Some also believe that these treasures can be equated with the "forfedha of the ogham." I have tried looking up 'forfedha' and have not been able to find it, but I would assume that it means the magic and power behind the ogham. Below are a couple posts that I have saved on the topic which also discuss the stance of the crane as being magical. Ruadha/n