From the Augustinian web site:
The Conversion of Saint Augustine
During the Easter Vigil, on the night between April 24 and 25, 387, Augustine was baptized by Bishop Ambrose in the Cathedral of Milan together with his son, Adeodatus, and a small group of friends, including the ‘brother of (his) heart’, Alypius. Thus was brought to its happy end the long and tiring journey of Augustine’s conversion to the Catholic faith. Augustine himself records in Book 8 of the Confessions the climactic moment in which he surrendered to God’s grace and was relieved of the doubts and fears which had so long kept him imprisoned. How many things came together now in one moment to bring him freedom: the story of a visiting countryman, the song of a young child, the Letter of St. Paul, and most of all, the descent into misery that was ready to give way to the power of grace. “How sweet did it suddenly become to me to be free of the sweets of folly: things that I once feared to lose it was now joy to put away. You cast them forth from me, you the true and highest sweetness, you cast them forth, and in their stead you entered in, sweeter than every pleasure…(Conf. 9, 1).
Certainly the story of Augustine’s conversion numbers among the most well-known and most significant of all of Christian history: well-known, through Augustine’s own recording of it in his Confessions; significant, not only for the impact which his life of faith – as monk, bishop, and theologian – has had on the Catholic Church ever since, but also on the many men and women of every period whose own personal lives have been altered by reading it.