Finally, Justinian dispatched a force of approximately 35,000 men (2,000 men were detached and sent to invade southern Visigothic Hispania) under the command of Narses. The army reached Ravenna in June 552 and defeated the Ostrogoths decisively within a month at the battle of Busta Gallorum in the Apennines, where Totila was slain. After a second battle at Mons Lactarius in October that year, the resistance of the Ostrogoths was finally broken. In 554, a large-scale Frankish invasion was defeated at Casilinum, and Italy was secured for the Empire, though it would take Narses several years to reduce the remaining Gothic strongholds. At the end of the war, Italy was garrisoned with an army of 16,000 men. The recovery of Italy cost the empire about 300,000 pounds of gold. Procopius estimated "the loss of the Goths at 15,000,000."