The First Painting

The First Painting was an altered representation of one of Aguilar de Nerha's genetic memories.

Aguilar's Journal
''Da Vinci's paintings cannot stay in the Inquisition hands! Captain Diego has given away each piece to his underlings, and they are now scattered across Spain. We must recover all the pieces so the set can finally be sold to finance our fight against the Templars.''

''The first piece was given to Diego's personal confessor, the Abbot of Snata Claudia de Las Huelgas, and is being stored in his abbey. We will sneak and lockpick our way through and recover the painting.''

Reference

 * Assassin's Creed: Rebellion