The downloadable content will fill out the missing memory blocks in Assassin’s Creed II. The titles of the content are telling in themselves. The battle of Forli most likely deals with the town being seized by Cesare Borgia (The villain in ACII) in 1499. Control of the town had previously been claimed by Pope Sixtus IV and given to his nephew Gerolamo Riario. Riario’s wife was the beautiful Caterina Sforza, who fans of the game might remember running into as Ezio tried to board a boat to Venice. It’s possible that the plot aligns Ezio with Caterina as she fights for the town’s independence.

Source [IGN]