The Romans unified their country with more than just leadership, for they were the inventors of concrete. Concrete, while a boring topic, was the most useful out of all of Rome’s inventions. Concrete is still used today and is why many ancient Roman buildings are still standing even after centuries of withstanding harsh elements. Rome was not stingy with their inventions, shown by the fact that concrete can be seen being used all around the world. Many countries were more than happy to unite with Rome after seeing their inventions and as a result Rome boosted the rest of the world into the renaissance. Rome may have been known for being cruel and brutal in battle, however we as a society must always be greatful for their inventions as we would not be here today without them.
Also you could talk about how they were the first society to invent democracy, but I didn’t know if you needed inventions or forms of government.