[FlashGit]

The Romans weren't afraid to win wars by attrition. Some of their generals were definitely good but they could just swarm any opposing force with highly disciplined, well armed troops.

Hannibal crushed the Romans several times, it didn't matter. Carthage still got wiped off the map.

[EGreg]

Who dealt Rome the most damage?

Spartacus and the Slave Wars

Hannibal and Carthage

Bar Kohkba and the Judaic Wars?

[yk]

In a single event, the Roman navy during the first Punic war. Rome lost the entire invasion fleet with estimates of more than 90.000 drowned during a storm. (It is still the second worst maritime disaster in history as Wikipedia counts. [0] Wikipedia lists the Mongol invasion of Japan as the worst, with more than 100.000 lives lost.)

The bloodiest war in Roman history was the second Punic war, that is the battles lost against Hannibal.

[0] https://en.wikipedia.org/wiki/List_of_maritime_disasters

[EGreg]

What about the sinking of the Spanish armada invading Britain? As far as maritime disasters it was pretty huge. And that seems to have turned the tide of history.

[_delirium]

That's third on the list linked above, with estimated 15-20k men lost.

[boomboomsubban]

Persians, only the Romans can compete. They only stopped being a problem when the Muslims replaced them.