This castle owes its existence to a primal age in history. It was existing before the time of St Patrick for we hear many stories relating to its connection with this great saint.
It is supposed that St. Patrick during his mission in Donaghmoyne was invited to a feast at Manann's Castle. Manann had arranged to poison St Patrick. One of the butlers knowing of the treacherous expedient secretly told St Patrick not to eat the meat served on a certain dish. St Patrick refused this meat.The failure of his plans sorely perplexed Manann and so he made an effort to kill St Patrick but did not succeed. It is believed that Manann was afterwards changed into a salmon, put into a bottle & drowned.