To analyze Livy's History, it's important to begin with the facts. Livy was likely a contemporary of Augustus Caesar, around 50 BC. Other sources tell of a 142 installment history, of which only about a fourth of the books have survived. That means that Livy's The Rise of Rome is incomplete, and the full scope of the project was about 800 years. He compiled the history as a service to the emperor, and so there are mythic elements to the story that connect all the way through the 800 year history, tying Augustus's authority back to the gods, back all the way in time to the fall of Troy and the the foundations of Rome by Romulus and Remus.
But what does it mean? Well for one, it means that history is an important practice. This may seem commonplace today, since we've all read dozens of history books, especially in school, but in Livy's time, history wasn't common at all. In fact, Livy probably had to literally walk to people's houses (socially important people, that is), ask them about their family history. Historians have also argued that most of what the Roman's considered "history" at that time was really more like myths and rumors. So not only did Livy have to compile several different accounts, he had to not only make them fit together, he also had to keep the wealthy and powerful Romans happy whose families were included.
So the book is about power. By the way, there is reason to believe that the origins of history tend to follow this outline, where a king or ruler will command or request that one of his highest academics try to compile a history.
That brings us to the center of the analysis. The real intent of the history is to glorify the emperor by explaining that this authority is ancient, going back in time all the way to the war of Homer's Iliad.
By the way, the story of Aeneas travelling from Troy toward Rome, and the story of the birth of Romulus and Remus, those are both well-known stories, and history doesn't lie—Livy's history was at the center of Western literature for a long time afterward. Any classical education still includes a study of Rome, and Livy's The Rise of Rome is still an authoritative account of Rome's formation, however mythic is might be. So its influence is still reaching into the present moment, and Livy's contribution to the development of Western society simply cannot be overstated. This was one of the most important projects that every happened, and it's easy to see how such an academic project might be at the cornerstone for the Western mode of thought.
