The Roman Empire, founded in 27 BC by Augustus Caesar, lasted until 480 AD in the West and 1453 AD in the East, marked by significant emperors and events. Key aspects included the conquest of Britannia, public entertainment through 'bread and circuses,' and the rise of Christianity, culminating in its adoption as the state religion by Emperor Constantine. The empire faced decline starting around 192 AD, experiencing invasions and ultimately falling in 476 AD, while the Eastern Roman Empire continued as the Byzantine Empire for another thousand years.