This project is an analysis of the manuscript written by M. Fdez. Sidrón in 1735 signed in the Library of the University of La Laguna as (83/1-5).
Nevertheless, the principal aim of the study is to show the relation that the author established between San Borondón and St. Brendan of Clonfert, as well as to give a Spanish version of the text published in 1647 by J. Colgan De egressione familie Sancti Brendani, partly related with the tradition of the Nauigatio Sancti Brendani.