The hill of Knockea was where Lómán, the King of Uí Fidhgeinte met St Patrick. Lómán ordered a feast to be prepared for Patrick, and Mantán, a deacon in Patrick's group, assisted in preparing the feast. A company of jugglers arrived and asked Patrick for food. Patrick sent them to ask Lómán or Mantán for food but both men refused the jugglers.
Just then a youth named Neassán appeared carrying a cooked ram on his back for the feast. His mother accompanied him. Patrick asked Neassán for the ram and Neassán gave it to Patrick against his mother's wishes. Patrick then gave the ram to the jugglers and instantly the ground opened and swallowed them. Patrick cursed Lómán and Mantán and baptized Neassán, making him a deacon and founded a church for him in Mungret.
It is said that Patrick fasted and prayed for forty days and nights on Knockea hill and that the impression of his knees and thighs are on the rock where he knelt. Patrick then went onto Donaghmore where he baptized the people and built a church. Some of the tribes of the area came to Patrick and he baptized them and blessed their lands to the north from the hill of Finne, which was north-west of Donaghmore.
Knockea hill was excavated by archaeologists in 1960 under the leadership of Professor M. J. O'Kelly. They uncovered ringforts, houses and a burial place that was believed to date from pre-Christian times.
There is a story, related to Cahernorry Hill, about Fionn and the Fianna and their adventure in a strange underworld. They were lost in dense fog when they stumbled across a house. In the house, they found Cuanna, the fairy chief, a grey haired twelve-eyed man, a beautiful young woman, and an old woman with a cloak and a ram. A meal was prepared for them and the ram complained that portions of the food were unfair. The ram ate Fionn's portion and each of the Fianna tried to tie the ram to the wall but was unable to. However, the old man captured the ram without any problem and threw him out of the house.
The old woman threw her cloak over the men from the Fianna and turned them into old men. When the cloak was removed they returned to their normal forms. Cuanna explained to Fionn that the ram signified humanity, the old man represented the world, the old woman represented old age and the young woman could travel faster in a second than a person could in forty years. Cuanna then told Fionn not to worry about this too much.