After Hannibal had invaded Italy,1
Marcellus was sent to Sicily with a fleet. And when the disaster at Cannae came,2
and many thousands of Romans had been slain in the battle, and only a few had saved themselves by flying to Canusium, and it was expected that Hannibal would march at once against Rome, now that he had destroyed the flower of her forces,
in the first place, Marcellus sent fifteen hundred men from his ships to protect the city; then, under orders from the senate, he went to Canusium, and taking the troops that had gathered there, led them out of the fortifications to show that he would not abandon the country. Most of the leaders and influential men among the Romans had fallen in battle; and as for Fabius Maximus, who was held in the greatest esteem for his sagacity and trustworthiness, his excessive care in planning to avoid losses was censured as cowardly inactivity.
The people thought they had in him a general who sufficed for the defensive, but was inadequate for the offensive, and therefore turned their eyes upon Marcellus; and mingling and uniting his boldness and activity with the caution and forethought of Fabius, they sometimes elected both to be consuls together, and sometimes made them, by turns, consul and proconsul, and sent them into the field.
Poseidonius says that Fabius was called a shield, and Marcellus a sword.3
And Hannibal himself used to say that he feared Fabius as a tutor, but Marcellus as an adversary; for by the one he was prevented from doing any harm, while by the other he was actually harmed.