A member of the Parte Guelfa in Florence, a follower of Catheirne’s teaching, and son of Lapo di Castiglionchio. Suzanne Noffke described his activities, “He was Florentine ambassador to Siena in March 1375 and member of the Signoria of Florence during March and April 1376,” she continued to speculate that he might have, “assured Catherine of the city’s support in her negotiations with Gregory XI for peace.”1