Different answers for this own.
One could be governmental. When the Roman General Julius Caesar passed the Rubocorn River, this was consider an act of war. He had people called himself a dictator. (Bruus and friends stabbed him on 3/11.)
Another option, could be when Rome made the decision to fight the Carthargians. After a series of three wars, Rome won. This moved them to top dogs owning the Mediterran Sea, as their lake.