Bernardone, Francesco (c1181 - 1226): Better known as Francis of Assisi, Catholic saint, founder of the Franciscan Order of monks, and lover of Nature.
Catholic Encyclopędia - St. Francis of Assisi Delighting to commune with wild flowers and birds, greeting the Sun as it rose over the Umbrian vale, Francis' "gift of sympathy" was wider than the Apostles', who showed no love for Nature or for animals.
The Patron Saint of Greenies Two books, reviewed here by the New York Times, take very different approaches to Francis of Assisi, who had a streak of something close to Pantheism in him, causing him to revere Brother Fire so much that he refused to snuff out candles.