The lower and earlier of the two churches comprising the Basilica di San Francesco, this basilica was commissioned by Pope Gregory IX in 1228, just two years after St Francis' death, and completed in 1230. Its dark interior features a stunning series of frescoes and several stained-glass windows, the work of master craftsmen brought in from Germany, England and Flanders during the 13th century.

　　The tomb of St Francis lies in the Cripta di San Francesco beneath the main altar.