Home of St. Francis (6)
I believe the answer is:
'home of st francis' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for assisi that I've seen before include "Home town of St Francis" , "Italian city, associated with St Francis" , "Italian town associated with St Francis" , "St Francis's town" , "Homeplace of St Francis" .)