Find some information about the life of Saint Francis (biography) and the time in which he was living (historical, social, economical background).
Draw a timeline (= list of events in chronological order: a long bar labelled with dates and events; or: a table with three columns: date - life of Francis - socio-historical background) which illustrates the connection of biography and history.
Here are some useful sources:
in English
in German
https://www.zeit.de/2011/52/Ausstellung-Franziskus (anlässlich einer Ausstellung; viel aktueller Bezug)
http://www.kulturwest.de/kulturgeschichte/detailseite/artikel/der-zu-den-voegeln-sprach/ (describing an exhibition about Francis' life)
http://kiwithek.kidsweb.at/index.php/Franz_von_Assisi (very short biography)
https://www.lernhelfer.de/schuelerlexikon/kunst/artikel/italien-bis-zum-quattrocento (historical and social background)
(biography, made by students, class 11, of "Ratsgymnasium Wiedenbrück)
in Italian
(medieval context)