Born 1521 at Castronuovo (Potenza), a small town in Sicily; died 10 November, 1608. His baptismal name was Lancelotto, which out of love for the cross he changed into Andrew when he entered the Order of Theatines. His parents were
Giovanni and Margherita Apelli. After receiving his elementary training in the school of Castronuovo, he was sent to Venice to pursue a course in the humanities and in philosophy. He went to Naples to study canon and civil law, obtained the degree of Doctor of Laws and was ordained priest at the age of twenty-six, in 1545. For some time he held the office of lawyer at the ecclesiastical court of Naples. He later renounced his profession as ecclesiastical lawyer, having experienced that this professional exercise endangered his spiritual life, and for some time devoted himself entirely to holy meditation and other spiritual exercises.

The Archbishop of Naples now commissioned him to reform a convent at Naples, which by the laxity of its discipline had become a source of great scandal. By his own example and his untiring zeal he restored the religious discipline of the convent but not without many and great difficulties. He resolved to devote himself entirely to God and he entered the Order of Theatines, which had but recently been founded by St. Cajetan. On the vigil of the Assumption he was invested, being then thirty-five years of age.

After completing his novitiate, he obtained permission to visit the tombs of the Apostles and the Martyrs at Rome, and, upon his return was made master of novices. After holding this office ten years he was elected superior. His holy zeal for strict religious discipline, and for the purity of the clergy, as well as his deep humility and sincere piety induced the General of his Order to entrust him with the foundation of two new Theatine houses, one at Milan, the other at Piacenza.