Order of Theatines, which had but recently been founded by Saint 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.
By his efforts many more Theatine houses rose up in various diocese of Italy.
As superior of some of these new foundations he was so successful in converting sinners and heretics by his prudence in the direction of souls and by his eloquent preaching, that numerous disciples thronged around him, eager to be under his spiritual guidance.
One of the most noteworthy of his disciples was Lorenzo Scupoli, the author of that still popular book "The Spiritual Combat".
Saint Charles Borromeo was an intimate friend of Avellino and sought his advice in the most important affairs of the Church.
Through indefatigable in preaching, hearing confessions, and visiting the sick, Avellino still had time to write some ascetical works.
His letters were published in 1731, at Naples, in two volumes, and his other ascetical works, three years later in five volumes.
On 10 November 1608, when beginning the Holy Sacrifice of the Mass, he was stricken with apoplexy, and after devoutly receiving the Holy Viaticum, died the death of a saint at the age of eighty-eight.
In 1624, only sixteen years after his death, he was beatified by Urban VIII, and in 1712 was canonized by Clement XI.
He is venerated as patron by Naples and Sicily and invoked especially against a sudden death.
His earthly remains lie buried in the Church of Saint Paul at Naples.
from the 1907 Catholic Encyclopedia
