He grew up amid the violence and brutality of Renaissance Italy and witnessed the murder of two of his brothers. In 1576, at age 8, he was sent to Florence along with his younger brother, Rodolfo, to serve at the court of the Grand Duke Francesco I de' Medici and to receive further education. While there, he fell ill with a disease of the kidneys, which troubled him throughout his life. While he was ill, he took the opportunity to read about the saints and to spend much of his time in prayer. He is said to have taken a private vow of chastity at age 9. In November 1579, the brothers were sent to the Duke of Mantua. Aloysius was shocked by the violent and frivolous lifestyle he encountered there.