There is some debate whether or not St Francis, born 1181/82 founder of the monastic order of Franciscans was a vegetarian, however because of his great compassion towards animals I would well imagine that he abstained from meat or at the least ate meat sparingly. Also it was also usual in monastic orders in those days to abstain from eating meat.
Most certainly St Francis, the patron Saint of animals, is remembered for his compassion towards animals and it was said that animals, most particularly a lamb, followed him everywhere. Animals where drawn to him and it is said that his donkey cried, when on his deathbed the dying saint thanked him for carrying him around throughout this life.
Stories abound concerning Saint Francis' great love for animals.
For Saint Francis all creatures were equals not as subjects to be dominated, exploited or abused. Saint Francis was a true steward, a caretaker of Gods precious creation, a brother to the animals, all animals without discrimination.
It is said that the Saint often sang and preached directly to birds and other animals praising God’s presence in each of them, one of the most famous and delightful of these instances is the account of the saint preaching to his "sister birds" in Fioretti di San Francesco, The Little Flowers of Saint Francis, a collection of charming anecdotes, pious and miraculous examples, from the life of Saint Francis and his followers composed at the end of the 14th century. One day whilst wandering with his companions he stopped at a place along the road where numerous birds sat in the trees, announcing to his companions that he wished to speak to his "sister birds" .