This book covers the first five volumes that Livy wrote (unfortunately the majority of what he put together has been lost to time), and the version I bought was translated by Aubrey De Selincourt. It describes the events that occurred from just prior to the foundation of Rome through to the kingship of Romulus and his successors and finishes after about three or four centuries after Rome's founding.
The book's very easy to read and engaging throughout. It is worth pointing out that Livy takes a somewhat credulous view of ancient superstitions (things like a boy's head being on fire while he's asleep, but he's fine), making it more like Herodotus than Thucydides when it comes to a commitment to absolute accuracy/realism.
It's fascinating to read about the development and growth of Rome as the patricians and plebeians tussled for power and new offices and powers were created to try and soothe the almost unending tensions between the two sides. Livy seems to favour the patricians most of the time, although given he was writing about events centuries before his time it makes it hard to see whether that's necessarily bias or simply an accurate reflection of the tribunes acting like a bunch of rabble-rousing idiots.
There is a sense that he's instilling into his ancestors quite a lot of virtue, in contrast with the lack of such in his own time (a theme that seems constant throughout human history). On the other hand, the imperial system did lead to a degeneration of Roman virtues and serial regicide, so maybe he had a point.
It's mostly historical but there are elements of myth, as mentioned above. Lots of the little stories (Gaius Mucius Scaevola, Horatio and the bridge and so on) are well-known in their own right.
So, provided you don't mind your history peppered with myth it's a highly enjoyable read and I'd recommend it to anyone who has an interest in classical history.