The dates of his birth and of his becoming a Franciscan are not known; a native of Assisi, he was one of the small group of most trusted companions of the saint during his last years.

[1] Although not one of the original twelve companions of Francis, Leo was one of the first to join him after the approbation of the first Rule of the Friars Minor (1209-1210) and perhaps was already a priest.

He was with Francis when the latter retired to Fonte Colombo near Rieti in 1223 to re-write the rule of the order, and he accompanied him on his subsequent journey to Rome to seek its approval.

After suffering many persecutions from the dominant party in the order, he died at the Porziuncola in extreme old age, and his remains are buried in the Basilica of St.

[5] Leo figures prominently in Nikos Kazantzakis' book Saint Francis, or God's Little Pauper.