Old Times
You’ve got to like the place Mary Beard chooses as a starting point for her history of Rome: 8 November of 63 BCE, the date of Cicero’s first oration against Cataline. This leaps right into the midst of things with a vengeance, and we start with the Roman whom, for better or worse, we know best. Presently, no doubt, we’ll head back toward Romulus.
Then again, you can’t beat Gibbon for getting right down to things:
In the second century of the Christian era, the Empire of Rome comprehended the fairest part of the earth, and the most civilised portion of mankind. The frontiers of that extensive monarchy were guarded by ancient renown and disciplined valour. The gentle but powerful influence of laws and manners had gradually cemented the union of the provinces. Their peaceful inhabitants enjoyed and abused the advantages of wealth and luxury. The image of a free constitution was preserved with decent reverence: the Roman senate appeared to possess the sovereign authority, and devolved on the emperors all the executive powers of government. During a happy period (A.D. 98-180) of more than fourscore years, the public administration was conducted by the virtue and abilities of Nerva, Trajan, Hadrian, and the two Antonines. It is the design of this, and of the two succeeding chapters, to describe the prosperous condition of their empire; and afterwards, from the death of Marcus Antoninus, to deduce the most important circumstances of its decline and fall; a revolution which will ever be remembered, and is still felt by the nations of the earth.