The decorative cycle of the transepts is made up of thirty-seven painted canvases which sequentially describe the Stories of Abraham, Isaac, Jacob and Joseph.
A vast Old Testament structure with inscriptions explaining relevant biblical events in the Christian tradition. Christ is the fulfillment of the promise made by God to Abraham of numerous descendants: “And simply by being Christ’s, you are that progeny of Abraham, the heirs named in the promise.” (Letter of St. Paul to the Galatians 3:29.
The surviving narrative of these frescoes using a mixed technique begins at the first vault of the east aisle of the north transept near the presbytery, with the story with Hagar who takes refuge in the desert, then continues north making the whole round and returning to the presbytery, the theological point of reference.
It is difficult to attribute the authors and the exact dates of these works, presumably from the second half of the 1300s.
- Vault 1 - North (east nave)North transept, east side nave, third bay. Near the Altar of San Michele Arcangelo (St. Michael the Archangel).
Sarai mistreats expectant Hagar | Intervention of the Angel of the Lord | Return of Hagar | Birth of Ishmael
- Vault 2 - North (east nave)North transept, east nave, second span. Near the Altar of the Deposition.
- Vault 3 - North (east nave)North transept, first span east nave. Near the Altar of San Nicola (St. Nicholas).
Lot and the two Angels | Lot and his family fleeing Sodom | Destruction of Sodom
- Vault 4 - North (west nave)North transept, third bay on the west side. Near the Altar of Sant’Antonio Abate (St. Anthony Abbot).
Rebecca offers a drink to Eliezer | Expectant Rebecca| Birth of Esau and Jacob | Esau sells the birthright to Jacob.
- Vault 3 - South (west nave)South transept, west nave, third bay. Near the sacristy of the Canons
- Vault 2 - South (west nave)South transept, west nave, second bay. Near the Altar of the Visitation.
Isaac blesses Jacob and sends him to Mesopopotania | Dream of Jacob | Jacob meets Rachel at the well | Agreement between of Jacob and Laban.
- Vault 1 - South (west nave)South transept, west nave, first span. Near the Altar of the Crucifix.
Jacob meets the angel | Jacob's struggle with the angel | Jacob shares his goods with Esau | Meeting between Esau and Jacob.
- Vault 1 - South (east nave)South transept, east nave, first span. Near the Altar of the Annunciation.
- Vault 2 - South (east nave)South transept, east nave, second span. Near the altar of San Benedetto (St. Benedict).
Joseph seduced by Potiphar’s wife | Joseph accused by Potiphar’s wife | Joseph interprets the dreams of the cupbearer and the baker | Joseph interprets Pharaoh’s dreams.
- Vault 3 - South (east nave)South transept, east side nave, third bay, near the sacristy.
Joseph appointed viceroy of Egypt | Joseph distributes the grain | The brothers meet Joseph without recognizing him | The brothers recognize Joseph
Stories of Joseph
Vault 1 - east nave
- Jacob sends Joseph to ShechemThe father sends his son to check on his brothers and the livestock
- The brothers plot to kill Joseph
- Ruben opposes the killing of JosephSimeon and Levi throw Joseph on the sacrificial altarSimeon and Levi throw Joseph on the sacrificial altar
- Joseph sold to the Ishmaelite merchantsJudah (checkered jacket) and the other brothers Simeon and Levi while they eat and drink.