 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 . 
