Reluctant Saint: The Life of Francis of Assisi by Donald Spoto
A book that looks at St. Francis within the context of the Medieval times and the zeitgeist of the Catholic Church. The author is a confirmed Christian and doesn't apologize for it. But he is not above criticizing the Catholic Church and the Medieval World. Indeed, he sees Francis as a heroic reformer of a sometimes corrupt Church. The author can be long winded at times.
Francis started out in life as a spoiled merchant's son and playboy. After spending some time as prisoner of war in a local dispute, he eventually has a religious conversion while sitting in an abandoned church. Eschewing both the hierarchy and social institutions of the church, as well as the sterile environment of learning Scripture without practicing it, Francis dedicates himself to a life of poverty and quietly caring for the poor and sick.
Francis is sometimes little more than a garden gnome in popular treatment. He did see beauty in nature, and treated animals with kindness. However, such things are probably overblown. Francis' primary mission was always serving the god of his understanding by administering to the poor and disaffected. Artistic renderings of Francis with birds and animals should be understood symbolically; in Medieval times, birds were symbols of human souls, ever ready to fly to heaven above the constraining feudalist society.
Overall, a decent read, and I can see why Francis is one of Catholicism's best loved saints.