Francesco Bernardone (Graham Faulkner) comes back home to Assisi in 1200 A.D. nervously exhausted by the wars. His well-to-do parents are quick to assure the townspeople that he is not a coward. The young man languishes in bed with nightmares of battle while his loving mother pampers him. His father, a brutish merchant obsessed with success, cannot understand his son's malady.

One day, Francesco alights from his bed at the chirping of a small bird. He follows a ray of sunshine to the balcony and then walks across the roof to fetch the bird. It is the beginning of his awakening to a new life. He spends days in the lush fields near Assisi. Claire (Judi Bowker), a pretty young neighbor, tells him that the villagers think he's berserk — after all, he loves flowers, chases butterflies, and sings like a bird. When he went off to war, he was judged sane and bright.

In the Roman Catholic church, the wealthy sit jewel-bedecked and passive while the poor are huddled in the rear of the church. During the Mass, Francesco sees the eyes of the kingly Christ on the altar cross open. He screams "No!" and is removed from the church. Later when he flings his father's silks and fine clothes to the poor of the streets, he is beaten and taken before the Bishop. There, in front of the authorities and the poor, Francesco makes his break with family and wealthy community. Quoting John 3:6 — "that which is born of the flesh is flesh and that which is born of the Spirit is spirit" — he takes off his clothes, giving them to his weeping father, and tells him that there are no more fathers, no more sons. He will become a beggar like Christ and seek happiness and peace of mind. He will be as free as the creatures of the earth.

Francesco's retreat is the beginning of a life of self-sacrifice. His friends eventually gather around him, and together they restore a ruined chapel in the fields near the city. There the poor, the physically scarred, and the weak find a home. Francesco and his community of brothers beg for food to survive and worship the Christ on the cross who died with his eyes open, a poor man. The simple folk come by droves to the community. But their church is burned by the Bishop in hopes that Francesco and his followers will be reconciled to the city. Instead, he goes to Rome to obtain a meeting with Pope Innocent III (Alec Guinness). Francesco is blessed and told that he puts the rich holy men to shame. He returns to Assisi renewed.

Franco Zeffirelli, Suso Cecchi D'Amico, Kenneth Ross, and Lina Wertmuller co-authored the screenplay with some fictionalizations added to the true story of St. Francis of Assisi. Brother Sun, Sister Moon is a gorgeous piece of filmmaking with opulent outdoor photography and stunning views of Assisi, the towers of San Gimignamo, and Monreale's great basilica. The folk songs — written and sung by Donovan — give the film its parabolic beauty and emotional impact. The fresh good looks and remarkably sensitive acting by Graham Faulkner and Judi Bowker (who joins Francesco and his brothers) most likely will draw many young people into this very touching account of the early life of St. Francis.