According to the Book of Invasions the first inhabitants of Ireland were led by Cesair, daughter of Bith and granddaughter of the Biblical Noah.
For reasons unknown Bith and Cesair were refused a place on the Ark by Noah. Bith, Cesair and their followers decided to built their own small fleet. Once completed the three ships set sail and arrived on Ireland after a seven years long journey. The composition of the fleet's passenger list is remarkable: beside a flock of sheep there were three men and 50 woman on board.
The men were divided among the women and the desire to populate Ireland was more then they could bare. Ladra was the first man to die of the excess of women. After his dead the women were redistributed among the remaining two men. One group, led by Bith, went north to disappear from the stage, while the other group, led by Cesair, had a serious problem when Fionntan, the only surviving man, escaped to Tul Tuinde, or the Hill of the Wave.
To make matters worse the Cesair, the leader of the tribe, died.
Without their leader to guide them and the only man on the run the perspectives of the tribe were far from optimistic. Their dire fate, a slow extinction due to the lack of offspring, was averted by the Biblical Flood which is said to have took place forty days after the Cesair had set foot on Irish soil. It would take 312 years for the next tribe, the Partholonians, to settle in Ireland.
The Cesair would have been forgotten if Fionntan did not survived both the women as the Flood.
Fionntan, also known as Fintan or Fintann or Fionntáin, was not an ordinary man. He managed to survive the Flood by transforming himself in a salmon. After many years he converted into an eagle and eventually he regained his human form.
According to the legends Fionntan, and his loyal companion, the magical hawk, lived for 5500 years. Because they were the repository of all knowledge of Ireland they acted as advisors for the future immigrants.
With the arrival of Christianity, and therewith the practice to put the legends and history in writing, Fionntan and his hawk decided to leave this world.
There is a delicate connection between Fionntan, the Cesair, and the legendary warrior Fionn MacCumhail. They both possessed all the knowledge and in both legends the salmon surface as Celtic symbol of wisdom.