He is said to have spent his early childhood in the care of Ita, abbess of a community in County Limerick, Ireland. He was educated by another saint, Eric - Bishop of Kerry, and during his long life is reputed to have paid visits to Columba, the charismatic missionary to the Picts in Scotland, and to Malo who had left his British home to preach the gospel in Brittany.
Some facts and a great deal of fiction are interwoven in the accounts of Brendan’s life. It is known that he lived and worked mainly in western Ireland and that he founded Clonfert monastery, of which he was abbot, in c. 559. But his fame rests on the mystical adventures later described in Brendan’s Voyage. This tenth-century romance tells of how Brendan and a company of monks sailed westwards over the Atlantic Ocean to a land of promise-- sometimes identified as the Canary Islands, but more likely to be wholly imaginary.
The exploits of the company are described. One of the most remarkable-- and the reason for Brendan’s association with whales-- was their landing on the back of a sleeping whale, which they thought was an island, to celebrate Mass at Easter. After the Mass, they lit a fire and started to prepare a banquet, but the great creature awoke from its slumbers and began to move, to the terror of the sailors; they rushed in haste to their ships and fled.