Biography is a written narrative of an individual’s life. It often (but not always) starts with the subject’s birth, early years, and death. It’s more than just a list of things that happened to someone - it addresses how the person reacted and was influenced by those things.

Autobiography is written by the subject themselves. It could be a standard self-told story recounting the person’s life. A memoir is different again - it focuses on certain aspects, times, or incidents. As the name suggests, it's more memories than the retracing of facts.

Some of the earliest Western biographies were written in Ancient Greece. During the Early Middle Ages, when learning and literacy were confined to the Catholic Church, most biographies were of the Church Fathers, saints, popes, and martyrs.

By the Late Middle Ages, kings, knights, and prominent figures were being written about. They were nearly always commissioned by the subject, and so were meant to burnish a reputation.

The Confessions of Saint Augustine (400 A.D.) is a spiritual autobiography by the Church Father and theologian Saint Augustine of Hippo. It’s generally considered to be the earliest example of the genre, and had a profound influence on subsequent sacral and spiritual biographies of the period.

In The Confessions, Augustine recounts his youth as a member of the Manichean religion, a gnostic sect. Augustine reveals his constant sinning “in the jungle of erotic adventures,” and his subsequent conversion to Christianity.

When Augustine receives a call from God, his response is basically, “OK, but not yet”. He’s enjoying himself too much. One episode has become famous: the stealing of pears. After this shocking theft, Augustine realizes that he stole for no other reason than the thrill of the crime.

Rather than just recounting a series of events, Augustine looks at the motives, spiritual and psychological, behind his actions. In this, we see how autobiography begins to change. The self-revelatory autobiography is born.

Another great spiritual autobiography, the first written in the English language, is The Book of Margery Kempe (late 15th century). Margery tells how a vain and prideful harridan like her  could be turned into a woman of God. Like Augustine, she looks back with horror at her former vanities and lax morality.

Margery’s is not a modern-style autobiography where everything happens in neat chronological order, so it takes some getting used to. But if you persevere you will find it pretty amusing and a unique first-hand view into pre-Shakespearean England.