How Did the Romans Manage to Build Such an Enormous Empire?

While Rome is most famously known for its accomplishments like the construction of aqueducts, sewers, roads, and impressive structures like the Pantheon, the Colloseum and other theaters, the achievements in Engineering and Architecture are just a fraction of the powers the Romans had. <br><br>But how did the Romans really manage to create an Empire that lasted for centuries and stretched across the entire globe? What were the biggest factors that influenced the growth of the Roman Empire? <br><br>&#x200B;